Tissue anchors with hemostasis seal

ABSTRACT

A tissue anchor is provided that includes a head connected to a shaft, and a tissue-coupling element extending from the shaft. When the tissue anchor is unconstrained, the head is coaxial with an axis of the shaft, and the tissue-coupling element is generally orthogonal to the axis and is shaped such that if the tissue-coupling element were to be projected onto a plane that is perpendicular to the axis, (a) at least 80% of an area of a projection of the tissue-coupling element on the plane would fall within a first angle of 180 degrees in the plane having a vertex at the axis, and (b) the area would partially overlap, at least 3 mm from the vertex, both rays of a second angle of between 45 and 180 degrees in the plane having the vertex at the axis. Other embodiments are also described.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.15/619,881, filed Jun. 12, 2017, which is a continuation of U.S.application Ser. No. 15/104,467, filed Jun. 14, 2016, now U.S. Pat. No.9,907,547, which is the U.S. national stage of International ApplicationPCT/IB2015/002354, filed Dec. 2, 2015, which claims priority from (a)U.S. Provisional Application 62/086,269, filed Dec. 2, 2014, and (b)U.S. Provisional Application 62/167,660, filed May 28, 2015, which areassigned to the assignee of the present application and each of which isincorporated herein by reference.

FIELD OF THE APPLICATION

The present invention relates generally to tissue anchors, andspecifically to tissue anchors for implantation in soft tissue, such ascardiac tissue.

BACKGROUND OF THE APPLICATION

Tissue anchors are used for anchoring elements, such as electrode leadsor sutures, to tissue, such as bone or soft tissue.

SUMMARY OF THE APPLICATION

Some embodiments of the present invention provide a tissue anchor thatcomprises (a) a shaft, (b) a head connected to a proximal portion of theshaft, and (c) a tissue-coupling element, which extends from a distalend of the shaft. The tissue-coupling element is off-center with respectto a central longitudinal axis of the shaft. This off-centerednessallows the tissue-coupling element to be rotated during implantation soas to avoid contact with a sensitive anatomic structure, such as a bloodvessel.

For some applications, a deployment tool is provided for delivering thetissue anchor, while in a constrained state, through a wall of a heartof a subject, typically by advancing a sharp distal piercing tip of thedeployment tool through the wall. A surgeon, after delivering thetissue-coupling element through the wall of the heart, ascertainswhether the tissue-coupling element overlies a coronary blood vessel,such as the right coronary artery (RCA). If the tissue-coupling elementoverlies the coronary blood vessel, the surgeon rotates the tissueanchor until the tissue-coupling element no longer overlies the coronaryblood vessel. The surgeon then brings the tissue-coupling element intocontact with an external surface of the heart, by applying tension tothe anchor head in the heart chamber.

The off-centeredness of the tissue-coupling element thus allows thesurgeon to select an anchoring site from a plurality of anchoring sitesaround an exit site of the anchor on the heart wall, without the need torelocate the exit site by removing the tissue-coupling element and againpenetrating the deployment tool through the heart wall to redeliver thetissue-coupling element. The off-centeredness of the tissue-couplingelement allows for the biasing of the tissue-coupling element away fromthe exit site, by rotating the tissue-coupling element to find a pointof minimal impact on the cardiac circulation.

Without the techniques of the present invention, the tissue-couplingelement might inadvertently compress a blood vessel, which might resultin cardiac complications including but not limited to angina, myocardialinfarction, reduced blood flow, and/or a reduction in circulationefficiency in cardiac tissue. Removal of such an improperly positionedtissue-coupling element might be required, which might result inadditional complications and injury to the patient.

For some applications, when the tissue anchor is unconstrained by thedeployment tool, (a) the shaft has a central longitudinal axis, (b) thehead is coaxial with the central longitudinal axis, and (c) thetissue-coupling element is shaped such that if the tissue-couplingelement were to be projected onto a plane that is perpendicular to thecentral longitudinal axis, (i) at least 80% (e.g., at least 90%, such asat least 95%) of an area of a projection of the tissue-coupling elementon the plane would fall within a first angle of 180 degrees in the planehaving a vertex at the central longitudinal axis, and (ii) the areawould partially overlap, at a distance of at least 3 mm from the vertex,both rays of a second angle of between 45 and 180 degrees in the planehaving the vertex at the central longitudinal axis.

For some applications, when the tissue anchor is unconstrained by thedeployment tool, a wire thereof (a) is shaped as an open loop (e.g., athree-dimensional open loop), such as a spiral (e.g., athree-dimensional spiral) around a center point, and (b) extends from adistal end of the shaft at a radially-outer end of the open loop, e.g.,spiral. Typically, the tissue-coupling element is non-helical when thetissue anchor is unconstrained by the deployment tool.

For some applications, the tissue anchor further comprises a flexibleelongate tension member, which is typically distinct from the wire ofthe tissue-coupling element, and which is fixed to a site on the openloop and crosses at least a portion of the open loop when the tissueanchor is unconstrained by the deployment tool. To this end, theflexible elongate tension member typically includes (a) a distal portionthat is fixed to a site on the open loop (such as on an outermost turnof the open loop), (b) a proximal portion, which has a longitudinalsegment that runs alongside at least a portion of the shaft, and (c) acrossing portion, which (i) is disposed between the distal and theproximal portions along the flexible elongate tension member, and (ii)crosses at least a portion of the open loop when the tissue anchor isunconstrained by the deployment tool. Tension is applied to thetissue-coupling element of the tissue anchor via the flexible elongatetension member. The applied tension is resisted by the outward force ofthe open loop. The applied tension compresses and stiffens the openloop. This arrangement of tension distribution may overcome any naturaltendency of the open loop to straighten if tension were to be appliedalong the central longitudinal axis via the shaft, and thus may allowthe application of a greater load to the open loop. It is noted that themaximum design stiffness of the open loop is constrained by the need forthe open loop to be straightened for delivery in a shaft of thedeployment tool.

For some applications, the head is shaped so as to define a passage inwhich the proximal portion of the flexible elongate tension member isslidably disposed. The flexible elongate tension member comprises alocking stopper, which is axially fixed to the proximal or the crossingportion of the flexible elongate tension member. The locking stopper andthe passage are sized and shaped such that the size and shape of thepassage prevent proximal movement of the locking stopper past thepassage. The locking stopper limits the total load that can be appliedto the open loop by the flexible elongate tension member, therebyreducing excessive, unnecessary strain on the open loop. Additional load(tension) that is applied by the flexible elongate tension member pullson the entire anchor, and does not further increase the load appliedacross the open loop.

Typically, the tissue anchor is configured to allow relative axialmotion between the at least a portion of the shaft and the longitudinalsegment of the proximal portion of the flexible elongate tension memberwhen the tissue anchor is unconstrained by the deployment tool. Suchaxial motion allows tension to be applied to the flexible elongatetension member without also being applied to the shaft, and allows theopen loop to be unwound and the flexible elongate tension member to bedisposed alongside a portion of the flexible elongate tension member.Typically, the longitudinal segment of the proximal portion of theflexible elongate tension member is coupled in sliding communicationwith the at least a portion of the shaft when the tissue anchor isunconstrained by the deployment tool. For some applications, the tissueanchor comprises one or more annular elements, which are disposed aroundthe at least a portion of the shaft, and couple the flexible elongatetension member in the sliding communication with the at least a portionof the shaft when the tissue anchor is unconstrained by the deploymenttool. For example, the annular elements may comprise one or morecollars, loops, or rings.

In experiments on porcine heart cadavers conducted by the inventors, atissue anchor comprising the spiral and the flexible elongate tensionmember remained firmly implanted in tissue of the ventricular wall,without damaging the tissue, and without fracturing of the anchor underhigh loads. The inventors found that loads of up to 25 N could be safetyapplied. It was noted that the tension applied through the flexibleelongate tension member was of a magnitude of three times that of theload that could be applied through the central longitudinal axis of theshaft.

For some applications, a tissue anchor system is provided, whichcomprises (a) a first off-center tissue anchor, such as described above,(b) a second tissue anchor, and (c) one or more tethers, which areconfigured to couple (i) the head of first tissue anchor to (ii) thesecond tissue anchor. For some applications, the second tissue anchorcomprises a helical tissue-coupling element. For other applications, thesecond tissue anchor comprises a stent. For applications in which thetissue anchor comprises the flexible elongate tension member, asdescribed above, the one or more tethers are fixed to the flexibleelongate tension member. When tension is applied to the one or moretethers, the tension is transmitted to the flexible elongate tensionmember, rather than to the shaft via the head.

For some applications, the tissue-coupling element comprises three ormore tines, such as four or more tines. In these applications, when thetissue anchor is unconstrained by the deployment tool, (a) the shaft hasa central longitudinal axis, (b) the tines extend radially outward fromthe central longitudinal axis in respective directions that are fixedwith respect to one another, and (c) the tissue-coupling element isshaped such that if the tissue-coupling element were to be projectedonto a plane that is perpendicular to the central longitudinal axis, atleast 80% of an area of a projection of the tissue-coupling element onthe plane would fall within an angle of 210 degrees in the plane havinga vertex at the central longitudinal axis.

For some applications, the tissue-coupling element further comprises oneor more membranes that are fixed to and extend betweencircumferentially-adjacent ones of the tines. The membranes and tinestogether might be considered to define a structure similar in somerespect to a bat wing, or a partial umbrella. The membranes may helpevenly distribute the force on the external surface of the heart appliedby the tissue-coupling element.

There is therefore provided, in accordance with an inventive concept 1of the present invention, apparatus for delivery in a constrained statewithin a deployment tool, the apparatus comprising a tissue anchor,which comprises:

a shaft;

a tissue-coupling element, which comprises a wire, which is shaped as anopen loop having more than one turn when the tissue anchor isunconstrained by the deployment tool; and

a flexible elongate tension member, which includes (a) a distal portionthat is fixed to a site on the open loop, (b) a proximal portion, whichhas a longitudinal segment that runs alongside at least a portion of theshaft, and (c) a crossing portion, which (i) is disposed between thedistal and the proximal portions along the flexible elongate tensionmember, and (ii) crosses at least a portion of the open loop when thetissue anchor is unconstrained by the deployment tool,

wherein the tissue anchor is configured to allow relative axial motionbetween the at least a portion of the shaft and the longitudinal segmentof the proximal portion of the flexible elongate tension member when thetissue anchor is unconstrained by the deployment tool.

-   Inventive concept 2. The apparatus according to inventive concept 1,    wherein the open loop is shaped as a spiral when the tissue anchor    is unconstrained by the deployment tool.-   Inventive concept 3. The apparatus according to inventive concept 2,    wherein the spiral is shaped as a three-dimensional spiral when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 4. The apparatus according to inventive concept 2,    wherein the spiral is shaped as an elliptical spiral when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 5. The apparatus according to inventive concept 1,    wherein the open loop is shaped as a three-dimensional open loop    when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 6. The apparatus according to inventive concept 5,    wherein, when the tissue anchor is unconstrained by the deployment    tool:

a greatest longitudinal dimension of the three-dimensional open loop,measured in parallel to a central longitudinal axis of the shaft, isbetween 1 and 5 mm, and a greatest lateral dimension of thethree-dimensional open loop, measured perpendicular to the centrallongitudinal axis, is between 4 and 20 mm.

-   Inventive concept 7. The apparatus according to inventive concept 1,    wherein the site is on an outermost turn of the open loop when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 8. The apparatus according to inventive concept 1,    wherein the site is on a second-to-outermost turn of the open loop    when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 9. The apparatus according to inventive concept 1,    wherein a radius of the flexible elongate tension member is less    than a radius of the wire.-   Inventive concept 10. The apparatus according to inventive concept    9, wherein the radius of the flexible elongate tension member is    less than 50% of the radius of the wire.-   Inventive concept 11. The apparatus according to inventive concept    1, wherein, when the tissue anchor is unconstrained by the    deployment tool and the flexible elongate tension member is    tensioned straight, if the tissue-coupling element and the flexible    elongate tension member were to be projected onto a plane that is    perpendicular to a central longitudinal axis of the shaft, an angle    between (a) the flexible elongate tension member and (b) a tangent    to the open loop at the site would be between 70 and 90 degrees.-   Inventive concept 12. The apparatus according to inventive concept    1, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop is shaped so as to define an outermost turn and asecond-to-outermost at least partial turn, and

the outermost turn at least partially overlaps the second-to-outermostat least partial turn.

-   Inventive concept 13. The apparatus according to inventive concept    1, wherein, when the tissue anchor is unconstrained by the    deployment tool, the open loop is shaped so as to define one or more    curved segments and one or more straight segments.-   Inventive concept 14. The apparatus according to inventive concept    13, wherein, when the tissue anchor is unconstrained by the    deployment tool, the open loop is shaped so as to define the one or    more curved segments and two or more straight segments.-   Inventive concept 15. The apparatus according to inventive concept    1, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto a central longitudinal axis of the shaft, and

a distance between (a) a radially-outer end of the open loop and (b) aradially-inner-most point of the open loop, measured perpendicular tothe central longitudinal axis, is equal to at least 30% of the greatestlateral dimension.

-   Inventive concept 16. The apparatus according to inventive concept    15, wherein a ratio of the greatest longitudinal dimension and the    greatest lateral dimension is between 1:2 and 1:18 when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 17. The apparatus according to inventive concept    1, wherein the shaft comprises a sealing element.-   Inventive concept 18. The apparatus according to inventive concept    1, wherein the shaft has a central longitudinal axis that is    straight when the tissue anchor is unconstrained by the deployment    tool.-   Inventive concept 19. The apparatus according to inventive concept    1, wherein the shaft is flexible.-   Inventive concept 20. The apparatus according to inventive concept    1, wherein the shaft and the tissue-coupling element are integral to    one another.-   Inventive concept 21. The apparatus according to inventive concept    1, wherein a cross-sectional area of the wire is at least 0.09 mm2.-   Inventive concept 22. The apparatus according to inventive concept    21, wherein the cross-sectional area of the wire is no more than 2.9    mm2.-   Inventive concept 23. The apparatus according to inventive concept    1, wherein the flexible elongate tension member comprises Nitinol.-   Inventive concept 24. The apparatus according to any one of    inventive concepts 1-23,

wherein the tissue anchor comprises a head connected to a proximalportion of the shaft,

wherein the head is shaped so as to define a passage in which theproximal portion of the flexible elongate tension member is slidablydisposed,

wherein the flexible elongate tension member comprises a lockingstopper, which is axially fixed to the proximal or the crossing portionof the flexible elongate tension member, and

wherein the locking stopper and the passage are sized and shaped suchthat the size and shape of the passage prevent proximal movement of thelocking stopper past the passage.

-   Inventive concept 25. The apparatus according to inventive concept    24, wherein the locking stopper is axially fixed to the proximal or    the crossing portion of the flexible elongate tension member at a    distance of between 7 and 22 mm from the site on the open loop.-   Inventive concept 26. The apparatus according to inventive concept    24, wherein, if the tissue-coupling element were straightened in an    elongated configuration, the locking stopper would be a distance of    between 7 and 12 mm from the passage.-   Inventive concept 27. The apparatus according to any one of    inventive concepts 1-23, wherein the site on the open loop is a    first site on the open loop, and wherein, when the tissue anchor is    unconstrained by the deployment tool and the flexible elongate    tension member is tensioned straight:

the open loop surrounds a center point,

the wire extends from the distal end of the shaft at a second site onthe open loop, and

if the tissue-coupling element and the flexible elongate tension memberwere to be projected onto a plane that is perpendicular to a centrallongitudinal axis of the shaft, an angle between the first and thesecond sites, having a vertex at the center point, would be between 130and 180 degrees.

-   Inventive concept 28. The apparatus according to inventive concept    27, wherein the angle is between 150 and 180 degrees.-   Inventive concept 29. The apparatus according to inventive concept    28, wherein the angle is between 170 and 180 degrees.-   Inventive concept 30. The apparatus according to inventive concept    27, the second site is at a radially-outer end of the open loop when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 31. The apparatus according to any one of    inventive concepts 1-23, wherein, when the tissue anchor is    unconstrained by the deployment tool:

the open loop surrounds a center point, and

(a) a site distance between the site and the distal end of the shaft isgreater than (b) a center-point distance between the center point andthe distal end of the shaft, when the tissue anchor is unconstrained bythe deployment tool.

-   Inventive concept 32. The apparatus according to inventive concept    31, wherein the site distance equals at least 150% of the    center-point distance when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 33. The apparatus according to inventive concept    32, wherein the site distance equals at least 175% of the    center-point distance when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 34. The apparatus according to any one of    inventive concepts 1-23, wherein the longitudinal segment of the    proximal portion of the flexible elongate tension member is coupled    in sliding communication with the at least a portion of the shaft    when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 35. The apparatus according to inventive concept    34, wherein the tissue anchor comprises one or more annular    elements, which are disposed around the at least a portion of the    shaft, and couple the flexible elongate tension member in the    sliding communication with the at least a portion of the shaft when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 36. The apparatus according to any one of    inventive concepts 1-23, wherein the flexible elongate tension    member is not fixed to any portion of the open loop beyond 2 mm from    the site on the open loop, measured when the tissue anchor is    unconstrained by the deployment tool.-   Inventive concept 37. The apparatus according to any one of    inventive concepts 1-23, wherein, when the tissue anchor is    unconstrained by the deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto a central longitudinal axis of the shaft, and

the flexible elongate tension member is not fixed to any portion of theopen loop beyond a distance from the site on the open loop, wherein thedistance equals 30% of the greatest lateral dimension.

-   Inventive concept 38. The apparatus according to any one of    inventive concepts 1-23, wherein the flexible elongate tension    member is fixed to the open loop only at the site on the open loop.-   Inventive concept 39. The apparatus according to any one of    inventive concepts 1-23, wherein, when the tissue anchor is    unconstrained by the deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto a central longitudinal axis of the shaft, and

the at least a portion of the open loop crossed by the crossing portionhas a length that equals at least 50% of the greatest lateral dimension.

-   Inventive concept 40. The apparatus according to inventive concept    39, wherein the length of the at least a portion of the open loop    crossed by the crossing portion equals at least 75% of the greatest    lateral dimension when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 41. The apparatus according to inventive concept    40, wherein the length of the at least a portion of the open loop    crossed by the crossing portion equals at least 90% of the greatest    lateral dimension when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 42. The apparatus according to any one of    inventive concepts 1-23, wherein the wire extends from a distal end    of the shaft at a radially-outer end of the open loop when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 43. The apparatus according to inventive concept    42, wherein, when the tissue anchor is unconstrained by the    deployment tool, the open loop surrounds a center point, and the    wire intersects the center point.-   Inventive concept 44. The apparatus according to inventive concept    42, wherein, when the tissue anchor is unconstrained by the    deployment tool, the open loop surrounds a center point, and the    wire does not intersect the center point.-   Inventive concept 45. The apparatus according to any one of    inventive concepts 1-23, wherein the wire extends from a distal end    of the shaft at a radially-inner end of the open loop when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 46. The apparatus according to inventive concept    45,

wherein the flexible elongate tension member is a first flexibleelongate tension member, the distal portion is a first distal portion,the proximal portion is a first proximal portion, the crossing portionis a first crossing portion, the site is a first site, the at least aportion of the open loop is at least a first portion of the open loop,and the longitudinal segment of the flexible elongate tension member isa first longitudinal segment of the first flexible elongate tensionmember,

wherein the tissue anchor comprises a second flexible elongate tensionmember, which includes (a) a second distal portion that is fixed to asecond site on the open loop, different from the first site, (b) asecond proximal portion, which has a second longitudinal segment thatruns alongside at least a portion of the shaft, and (c) a secondcrossing portion, which (i) is disposed between the second distal andthe second proximal portions along the second flexible elongate tensionmember, and (ii) crosses at least a second portion of the open loop whenthe tissue anchor is unconstrained by the deployment tool, and

wherein the tissue anchor is configured to allow relative axial motionbetween the at least a portion of the shaft and the second longitudinalsegment of the second proximal portion of the second flexible elongatetension member when the tissue anchor is unconstrained by the deploymenttool.

-   Inventive concept 47. The apparatus according to inventive concept    46, wherein the first proximal portion of the first flexible    elongate tension member and the second proximal portion of the    second flexible elongate tension member join one another.-   Inventive concept 48. The apparatus according to any one of    inventive concepts 1-23, wherein a proximally-facing surface defined    by the tissue-coupling element is concave when the tissue anchor is    unconstrained by the deployment tool.-   Inventive concept 49. The apparatus according to any one of    inventive concepts 1-23, wherein a proximally-facing surface defined    by the tissue-coupling element is convex when the tissue anchor is    unconstrained by the deployment tool.-   Inventive concept 50. The apparatus according to any one of    inventive concepts 1-23, wherein the apparatus further comprises one    or more tethers, which are fixed to the flexible elongate tension    member.-   Inventive concept 51. The apparatus according to any one of    inventive concepts 1-23,

wherein the tissue anchor is a first tissue anchor, and

wherein the apparatus further comprises:

-   -   a second tissue anchor, which is separate and distinct from the        first tissue anchor; and    -   one or more tethers, which are configured to couple (a) the        flexible elongate tension member to (b) the second tissue        anchor.

-   Inventive concept 52. The apparatus according to inventive concept    51, wherein the one or more tethers are fixed to (a) the flexible    elongate tension member and (b) the second tissue anchor.

-   Inventive concept 53. The apparatus according to inventive concept    51, wherein the one or more tethers are (a) fixed to the second    tissue anchor and (b) not fixed to the shaft of the first tissue    anchor.

-   Inventive concept 54. The apparatus according to inventive concept    51, wherein the second tissue anchor comprises a helical    tissue-coupling element.

-   Inventive concept 55. The apparatus according to inventive concept    51, wherein the second tissue anchor comprises a stent.

-   Inventive concept 56. The apparatus according to any one of    inventive concepts 1-23,

wherein the tissue anchor is a first tissue anchor, and

wherein the apparatus further comprises a second tissue anchor, which isseparate and distinct from the first tissue anchor, and

wherein the flexible elongate tension member is coupled to the secondtissue anchor.

-   Inventive concept 57. The apparatus according to inventive concept    56, wherein the flexible elongate tension member is fixed to the    second tissue anchor.-   Inventive concept 58. The apparatus according to any one of    inventive concepts 1-23,

further comprising a deployment tool, which comprises a sharp distalpiercing tip, and which is configured to constrain the tissue-couplingelement while delivering the tissue-coupling element through tissue, and

wherein, when the tissue-coupling element is constrained by thedeployment tool, a longitudinal portion of the flexible elongate tensionmember runs alongside a portion of the wire.

There is further provided, in accordance with an inventive concept 59 ofthe present invention, apparatus for delivery in a constrained statewithin a deployment tool, the apparatus comprising:

a tissue anchor, which comprises (a) a shaft, (b) a head connected to aproximal portion of the shaft, and (c) a tissue-coupling element, whichextends from a distal end of the shaft; and

a deployment tool, which comprises a sharp distal piercing tip, andwhich is configured to constrain the tissue-coupling element whiledelivering the tissue-coupling element through tissue,

wherein, when the tissue anchor is unconstrained by the deployment tool:

-   -   the shaft has a central longitudinal axis,    -   the head is coaxial with the central longitudinal axis, and    -   the tissue-coupling element is shaped such that if the        tissue-coupling element were to be projected onto a plane that        is perpendicular to the central longitudinal axis, (a) at least        80% of an area of a projection of the tissue-coupling element on        the plane would fall within a first angle of 180 degrees in the        plane having a vertex at the central longitudinal axis, and (b)        the area would partially overlap, at least 3 mm from the vertex,        both rays of a second angle of between 45 and 180 degrees in the        plane having the vertex at the central longitudinal axis.

-   Inventive concept 60. The apparatus according to inventive concept    59, wherein at least 95% of the area of the projection of the    tissue-coupling element on the plane would fall within the first    angle.

-   Inventive concept 61. The apparatus according to inventive concept    59, wherein at least 80% of the area of the projection of the    tissue-coupling element on the plane would fall within a third angle    of 150 degrees in the plane having the vertex at the central    longitudinal axis.

-   Inventive concept 62. The apparatus according to inventive concept    59, wherein an outer portion of the area of the projection of the    tissue-coupling element on the plane would fall within all angular    positions of a fourth angle of 90 degrees in the plane having the    vertex at the central longitudinal axis, which outer portion    consists of all points of the area at least 3 mm from the vertex.

-   Inventive concept 63. The apparatus according to inventive concept    59, wherein a proximally-facing surface defined by the    tissue-coupling element is concave when the tissue anchor is    unconstrained by the deployment tool.

-   Inventive concept 64. The apparatus according to inventive concept    59, wherein, when the tissue anchor is unconstrained by the    deployment tool:

a greatest longitudinal dimension of the tissue-coupling element,measured parallel to the central longitudinal axis, is between 1 and 5mm, and

a greatest lateral dimension of the tissue-coupling element, measuredperpendicular to the central longitudinal axis, is between 4 and 20 mm.

-   Inventive concept 65. The apparatus according to inventive concept    64, wherein a ratio of the greatest longitudinal dimension and the    greatest lateral dimension is between 1:2 and 1:18 when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 66. The apparatus according to inventive concept    59, wherein the tissue-coupling element has a length of 5 to 60 mm    when constrained into a straight configuration.-   Inventive concept 67. The apparatus according to inventive concept    59, wherein the tissue-coupling element has one or more distal ends,    each of which does not define a sharp distal tip.-   Inventive concept 68. The apparatus according to inventive concept    67, wherein each of the distal ends is blunt.-   Inventive concept 69. The apparatus according to inventive concept    59, wherein the tissue-coupling element is non-helical when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 70. The apparatus according to inventive concept    59, wherein the shaft comprises a sealing element.-   Inventive concept 71. The apparatus according to inventive concept    59, wherein the central longitudinal axis is straight when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 72. The apparatus according to inventive concept    59, wherein the shaft is flexible.-   Inventive concept 73. The apparatus according to inventive concept    59, wherein the shaft and the tissue-coupling element are integral    to one another.-   Inventive concept 74. The apparatus according to inventive concept    73, wherein the shaft and the tissue-coupling element comprise a    wire.-   Inventive concept 75. The apparatus according to inventive concept    59, wherein the deployment tool comprises a hypodermic needle.-   Inventive concept 76. The apparatus according to any one of    inventive concepts 59-75, wherein the tissue-coupling element    comprises at least three tines that extend radially outward from the    central longitudinal axis in respective directions that are fixed    with respect to one another when the tissue anchor is unconstrained    by the deployment tool.-   Inventive concept 77. The apparatus according to inventive concept    76, wherein the tines comprise at least four tines.-   Inventive concept 78. The apparatus according to any one of    inventive concepts 59-75, wherein the tissue-coupling element    comprises a wire.-   Inventive concept 79. The apparatus according to inventive concept    78,

wherein the wire is shaped as an open loop having more than one turn,when the tissue anchor is unconstrained by the deployment tool,

wherein the tissue anchor further comprises a flexible elongate tensionmember, which includes (a) a distal portion that is fixed to a site onthe open loop, (b) a proximal portion, which has a longitudinal segmentthat runs alongside at least a portion of the shaft, and (c) a crossingportion, which (i) is disposed between the distal and the proximalportions along the flexible elongate tension member, and (ii) crosses atleast a portion of the open loop when the tissue anchor is unconstrainedby the deployment tool, and

wherein the tissue anchor is configured to allow relative axial motionbetween the at least a portion of the shaft and the longitudinal segmentof the proximal portion of the flexible elongate tension member when thetissue anchor is unconstrained by the deployment tool.

-   Inventive concept 80. The apparatus according to inventive concept    79,

wherein the head is shaped so as to define a passage in which theproximal portion of the flexible elongate tension member is slidablydisposed,

wherein the flexible elongate tension member comprises a lockingstopper, which is axially fixed to the proximal or the crossing portionof the flexible elongate tension member, and

wherein the locking stopper and the passage are sized and shaped suchthat the size and shape of the passage prevent proximal movement of thelocking stopper past the passage.

-   Inventive concept 81. The apparatus according to inventive concept    79, wherein the open loop is shaped as a spiral when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 82. The apparatus according to inventive concept    81, wherein the spiral is shaped as a three-dimensional spiral when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 83. The apparatus according to inventive concept    81, wherein the spiral is shaped as an elliptical spiral when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 84. The apparatus according to inventive concept    79, wherein the open loop is shaped as a three-dimensional open loop    when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 85. The apparatus according to inventive concept    79, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop surrounds a center point, and

(a) a site distance between the site and the distal end of the shaft isgreater than (b) a center-point distance between the center point andthe distal end of the shaft when the tissue anchor is unconstrained bythe deployment tool.

-   Inventive concept 86. The apparatus according to inventive concept    85, wherein the site distance equals at least 150% of the    center-point distance when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 87. The apparatus according to inventive concept    86, wherein the site distance equals at least 175% of the    center-point distance when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 88. The apparatus according to inventive concept    79, wherein the site is on an outermost turn of the open loop when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 89. The apparatus according to inventive concept    79, wherein the site is on a second-to-outermost turn of the open    loop when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 90. The apparatus according to inventive concept    79, wherein a radius of the flexible elongate tension member is less    than a radius of the wire.-   Inventive concept 91. The apparatus according to inventive concept    90, wherein the radius of the flexible elongate tension member is    less than 50% of the radius of the wire.-   Inventive concept 92. The apparatus according to inventive concept    79, wherein the longitudinal segment of the proximal portion of the    flexible elongate tension member is coupled in sliding communication    with the at least a portion of the shaft when the tissue anchor is    unconstrained by the deployment tool.-   Inventive concept 93. The apparatus according to inventive concept    92, wherein the tissue anchor comprises one or more annular    elements, which are disposed around the at least a portion of the    shaft, and couple the flexible elongate tension member in the    sliding communication with the at least a portion of the shaft when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 94. The apparatus according to inventive concept    79, wherein the flexible elongate tension member is not fixed to any    portion of the open loop beyond 2 mm from the site on the open loop,    measured when the tissue anchor is unconstrained by the deployment    tool.-   Inventive concept 95. The apparatus according to inventive concept    79, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto the central longitudinal axis, and

the flexible elongate tension member is not fixed to any portion of theopen loop beyond a distance from the site on the open loop, wherein thedistance equals 30% of the greatest lateral dimension.

-   Inventive concept 96. The apparatus according to inventive concept    79, wherein the flexible elongate tension member is fixed to the    open loop only at the site on the open loop.-   Inventive concept 97. The apparatus according to inventive concept    79, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto the central longitudinal axis, and

the at least a portion of the open loop crossed by the crossing portionhas a length that equals at least 50% of the greatest lateral dimension.

-   Inventive concept 98. The apparatus according to inventive concept    97, wherein the length of the at least a portion of the open loop    crossed by the crossing portion equals at least 75% of the greatest    lateral dimension when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 99. The apparatus according to inventive concept    98, wherein the length of the at least a portion of the open loop    crossed by the crossing portion equals at least 90% of the greatest    lateral dimension when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 100. The apparatus according to inventive concept    79, wherein, when the tissue anchor is unconstrained by the    deployment tool and the flexible elongate tension member is    tensioned straight, if the tissue-coupling element and the flexible    elongate tension member were to be projected onto the plane that is    perpendicular to the central longitudinal axis, an angle between (a)    the flexible elongate tension member and (b) a tangent to the open    loop at the site would be between 70 and 90 degrees.-   Inventive concept 101. The apparatus according to inventive concept    79, wherein the site on the open loop is a first site on the open    loop, and wherein, when the tissue anchor is unconstrained by the    deployment tool and the flexible elongate tension member is    tensioned straight:

the open loop surrounds a center point,

the wire extends from the distal end of the shaft at a second site onthe open loop, and

if the tissue-coupling element and the flexible elongate tension memberwere to be projected onto the plane that is perpendicular to the centrallongitudinal axis, a third angle between the first and the second sites,having a vertex at the center point, would be between 130 and 180degrees.

-   Inventive concept 102. The apparatus according to inventive concept    101, wherein the third angle is between 150 and 180 degrees.-   Inventive concept 103. The apparatus according to inventive concept    102, wherein the third angle is between 170 and 180 degrees.-   Inventive concept 104. The apparatus according to inventive concept    101, the second site is at a radially-outer end of the open loop    when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 105. The apparatus according to inventive concept    79, wherein the flexible elongate tension member comprises Nitinol.-   Inventive concept 106. The apparatus according to inventive concept    79, wherein the apparatus further comprises one or more tethers,    which are fixed to the flexible elongate tension member.-   Inventive concept 107. The apparatus according to inventive concept    79,

wherein the tissue anchor is a first tissue anchor, and

wherein the apparatus further comprises:

-   -   a second tissue anchor, which is separate and distinct from the        first tissue anchor; and    -   one or more tethers, which are configured to couple (a) the        flexible elongate tension member to (b) the second tissue        anchor.

-   Inventive concept 108. The apparatus according to inventive concept    107, wherein the one or more tethers are fixed to (a) the flexible    elongate tension member to (b) the second tissue anchor.

-   Inventive concept 109. The apparatus according to inventive concept    107, wherein the second tissue anchor comprises a helical    tissue-coupling element.

-   Inventive concept 110. The apparatus according to inventive concept    107, wherein the second tissue anchor comprises a stent.

-   Inventive concept 111. The apparatus according to inventive concept    79,

wherein the tissue anchor is a first tissue anchor, and

wherein the apparatus further comprises a second tissue anchor, which isseparate and distinct from the first tissue anchor, and

wherein the flexible elongate tension member is coupled to the secondtissue anchor.

-   Inventive concept 112. The apparatus according to inventive concept    111, wherein the flexible elongate tension member is fixed to the    second tissue anchor.-   Inventive concept 113. The apparatus according to inventive concept    79, wherein, when the tissue-coupling element is constrained by the    deployment tool, a longitudinal portion of the flexible elongate    tension member runs alongside a portion of the wire.-   Inventive concept 114. The apparatus according to inventive concept    78, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the wire of the tissue-coupling element is shaped as an open loop havingmore than one turn around a center point, and

the wire extends from the distal end of the shaft at a radially-outerend of the open loop.

-   Inventive concept 115. The apparatus according to inventive concept    114, wherein the open loop is shaped as a spiral when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 116. The apparatus according to inventive concept    115, wherein the spiral is shaped as a three-dimensional spiral when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 117. The apparatus according to inventive concept    115, wherein the spiral is shaped as an elliptical spiral when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 118. The apparatus according to inventive concept    114, wherein the open loop is shaped as a three-dimensional open    loop when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 119. The apparatus according to inventive concept    114, wherein the wire intersects the center point when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 120. The apparatus according to inventive concept    114, wherein the wire does not intersect the center point when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 121. The apparatus according to inventive concept    114, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto the central longitudinal axis, and

a distance between (a) the radially-outer end of the open loop and (b) aradially-inner-most point of the open loop, measured perpendicular tothe central longitudinal axis, is equal to at least 30% of the greatestlateral dimension.

-   Inventive concept 122. The apparatus according to inventive concept    114, wherein a proximally-facing surface defined by the    tissue-coupling element is convex when the tissue anchor is    unconstrained by the deployment tool.-   Inventive concept 123. The apparatus according to inventive concept    78, wherein a cross-sectional area of the wire is at least 0.09 mm2.-   Inventive concept 124. The apparatus according to inventive concept    123, wherein the cross-sectional area of the wire is no more than    2.9 mm2.-   Inventive concept 125. The apparatus according to any one of    inventive concepts 59-75,

wherein the tissue anchor is a first tissue anchor, and

wherein the apparatus further comprises:

-   -   a second tissue anchor, which is separate and distinct from the        first tissue anchor; and    -   one or more tethers, which are configured to couple (a) the head        of the first tissue anchor to (b) the second tissue anchor.

-   Inventive concept 126. The apparatus according to inventive concept    125, wherein the one or more tethers are fixed to (a) the head of    the first tissue anchor to (b) the second tissue anchor.

-   Inventive concept 127. The apparatus according to inventive concept    125, wherein the second tissue anchor comprises a helical    tissue-coupling element.

-   Inventive concept 128. The apparatus according to inventive concept    125, wherein the second tissue anchor comprises a stent.

There is still further provided, in accordance with an inventive concept129 of the present invention, apparatus for delivery in a constrainedstate within a deployment tool, the apparatus comprising a tissueanchor, which comprises:

a shaft; and

a tissue-coupling element, which comprises a wire;

wherein, when the tissue anchor is unconstrained by the deployment tool:

-   -   the shaft has a central longitudinal axis,    -   the wire of the tissue-coupling element is shaped as an open        loop having more than one turn around a center point, and    -   the wire extends from a distal end of the shaft at a        radially-outer end of the open loop.

-   Inventive concept 130. The apparatus according to inventive concept    129, wherein the open loop is shaped as a spiral when the tissue    anchor is unconstrained by the deployment tool.

-   Inventive concept 131. The apparatus according to inventive concept    130, wherein the spiral is shaped as a three-dimensional spiral when    the tissue anchor is unconstrained by the deployment tool.

-   Inventive concept 132. The apparatus according to inventive concept    130, wherein the spiral is shaped as an elliptical spiral when the    tissue anchor is unconstrained by the deployment tool.

-   Inventive concept 133. The apparatus according to inventive concept    129, wherein the open loop is shaped as a three-dimensional open    loop when the tissue anchor is unconstrained by the deployment tool.

-   Inventive concept 134. The apparatus according to inventive concept    133, wherein, when the tissue anchor is unconstrained by the    deployment tool:

a greatest longitudinal dimension of the three-dimensional open loop,measured in parallel to the central longitudinal axis, is between 1 and5 mm, and

a greatest lateral dimension of the three-dimensional open loop,measured perpendicular to the central longitudinal axis, is between 4and 20 mm.

-   Inventive concept 135. The apparatus according to inventive concept    129, wherein the wire intersects the center point when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 136. The apparatus according to inventive concept    129, wherein the wire does not intersect the center point when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 137. The apparatus according to inventive concept    129, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto the central longitudinal axis, and

a distance between (a) the radially-outer end of the open loop and (b) aradially-inner-most point of the open loop, measured perpendicular tothe central longitudinal axis, is equal to at least 30% of the greatestlateral dimension.

-   Inventive concept 138. The apparatus according to inventive concept    134, wherein a ratio of the greatest longitudinal dimension and the    greatest lateral dimension is between 1:2 and 1:18 when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 139. The apparatus according to inventive concept    129, wherein the shaft comprises a sealing element.-   Inventive concept 140. The apparatus according to inventive concept    129, wherein the central longitudinal axis is straight when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 141. The apparatus according to inventive concept    129, wherein the shaft is flexible.-   Inventive concept 142. The apparatus according to inventive concept    129, wherein the shaft and the tissue-coupling element are integral    to one another.-   Inventive concept 143. The apparatus according to any one of    inventive concepts 129-142,

wherein the tissue anchor further comprises a flexible elongate tensionmember, which includes (a) a distal portion that is fixed to a site onthe open loop, (b) a proximal portion, which has a longitudinal segmentthat runs alongside at least a portion of the shaft, and (c) a crossingportion, which (i) is disposed between the distal and the proximalportions along the flexible elongate tension member, and (ii) crosses atleast a portion of the open loop when the tissue anchor is unconstrainedby the deployment tool, and

wherein the tissue anchor is configured to allow relative axial motionbetween the at least a portion of the shaft and the longitudinal segmentof the proximal portion of the flexible elongate tension member when thetissue anchor is unconstrained by the deployment tool.

-   Inventive concept 144. The apparatus according to inventive concept    143, wherein the site is on an outermost turn of the open loop when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 145. The apparatus according to inventive concept    143, wherein the site is on a second-to-outermost turn of the open    loop when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 146. The apparatus according to inventive concept    143, wherein a radius of the flexible elongate tension member is    less than a radius of the wire.-   Inventive concept 147. The apparatus according to inventive concept    146, wherein the radius of the flexible elongate tension member is    less than 50% of the radius of the wire.-   Inventive concept 148. The apparatus according to inventive concept    143, wherein, when the tissue anchor is unconstrained by the    deployment tool and the flexible elongate tension member is    tensioned straight, if the tissue-coupling element and the flexible    elongate tension member were to be projected onto a plane that is    perpendicular to the central longitudinal axis, an angle between (a)    the flexible elongate tension member and (b) a tangent to the open    loop at the site would be between 70 and 90 degrees.-   Inventive concept 149. The apparatus according to inventive concept    143, wherein the site on the open loop is a first site on the open    loop, and wherein, when the tissue anchor is unconstrained by the    deployment tool and the flexible elongate tension member is    tensioned straight:

the wire extends from the distal end of the shaft at a second site onthe open loop, and

if the tissue-coupling element and the flexible elongate tension memberwere to be projected onto a plane that is perpendicular to the centrallongitudinal axis, an angle between the first and the second sites,having a vertex at the center point, would be between 130 and 180degrees.

-   Inventive concept 150. The apparatus according to inventive concept    149, wherein the angle is between 150 and 180 degrees.-   Inventive concept 151. The apparatus according to inventive concept    150, wherein the angle is between 170 and 180 degrees.-   Inventive concept 152. The apparatus according to inventive concept    149, the second site is at a radially-outer end of the open loop    when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 153. The apparatus according to inventive concept    143, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto the central longitudinal axis, and

a distance between (a) a radially-outer end of the open loop and (b) aradially-inner-most point of the open loop, measured perpendicular tothe central longitudinal axis, is equal to at least 30% of the greatestlateral dimension.

-   Inventive concept 154. The apparatus according to inventive concept    143, wherein a cross-sectional area of the wire is at least 0.09    mm2.-   Inventive concept 155. The apparatus according to inventive concept    154, wherein the cross-sectional area of the wire is no more than    2.9 mm2.-   Inventive concept 156. The apparatus according to inventive concept    143, wherein the flexible elongate tension member comprises Nitinol.-   Inventive concept 157. The apparatus according to inventive concept    143, wherein (a) a site distance between the site and the distal end    of the shaft is greater than (b) a center-point distance between the    center point and the distal end of the shaft when the tissue anchor    is unconstrained by the deployment tool.-   Inventive concept 158. The apparatus according to inventive concept    157, wherein the site distance equals at least 150% of the    center-point distance when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 159. The apparatus according to inventive concept    158, wherein the site distance equals at least 175% of the    center-point distance when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 160. The apparatus according to inventive concept    143, wherein the longitudinal segment of the proximal portion of the    flexible elongate tension member is coupled in sliding communication    with the at least a portion of the shaft when the tissue anchor is    unconstrained by the deployment tool.-   Inventive concept 161. The apparatus according to inventive concept    160, wherein the tissue anchor comprises one or more annular    elements, which are disposed around the at least a portion of the    shaft, and couple the flexible elongate tension member in the    sliding communication with the at least a portion of the shaft when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 162. The apparatus according to inventive concept    143, wherein the flexible elongate tension member is not fixed to    any portion of the open loop beyond 2 mm from the site on the open    loop, measured when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 163. The apparatus according to inventive concept    143, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto the central longitudinal axis, and

the flexible elongate tension member is not fixed to any portion of theopen loop beyond a distance from the site on the open loop, wherein thedistance equals 30% of the greatest lateral dimension.

-   Inventive concept 164. The apparatus according to inventive concept    143, wherein the flexible elongate tension member is fixed to the    open loop only at the site on the open loop.-   Inventive concept 165. The apparatus according to inventive concept    143, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto the central longitudinal axis, and

the at least a portion of the open loop crossed by the crossing portionhas a length that equals at least 50% of the greatest lateral dimension.

-   Inventive concept 166. The apparatus according to inventive concept    165, wherein the length of the at least a portion of the open loop    crossed by the crossing portion equals at least 75% of the greatest    lateral dimension when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 167. The apparatus according to inventive concept    166, wherein the length of the at least a portion of the open loop    crossed by the crossing portion equals at least 90% of the greatest    lateral dimension when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 168. The apparatus according to inventive concept    143, wherein the apparatus further comprises one or more tethers,    which are fixed to the flexible elongate tension member.-   Inventive concept 169. The apparatus according to inventive concept    143,

wherein the tissue anchor is a first tissue anchor, and

wherein the apparatus further comprises:

-   -   a second tissue anchor, which is separate and distinct from the        first tissue anchor; and    -   one or more tethers, which are configured to couple (a) the        flexible elongate tension member to (b) the second tissue        anchor.

-   Inventive concept 170. The apparatus according to inventive concept    169, wherein the one or more tethers are fixed to (a) the flexible    elongate tension member and (b) the second tissue anchor.

-   Inventive concept 171. The apparatus according to inventive concept    169, wherein the second tissue anchor comprises a helical    tissue-coupling element.

-   Inventive concept 172. The apparatus according to inventive concept    169, wherein the second tissue anchor comprises a stent.

-   Inventive concept 173. The apparatus according to inventive concept    143,

wherein the tissue anchor is a first tissue anchor, and

wherein the apparatus further comprises a second tissue anchor, which isseparate and distinct from the first tissue anchor, and

wherein the flexible elongate tension member is coupled to the secondtissue anchor.

-   Inventive concept 174. The apparatus according to inventive concept    173, wherein the flexible elongate tension member is fixed to the    second tissue anchor.-   Inventive concept 175. The apparatus according to inventive concept    143, further comprising a deployment tool, which comprises a sharp    distal piercing tip, and which is configured to constrain the    tissue-coupling element while delivering the tissue-coupling element    through tissue, and

wherein, when the tissue-coupling element is constrained by thedeployment tool, a longitudinal portion of the flexible elongate tensionmember runs alongside a portion of the wire.

-   Inventive concept 176. The apparatus according to any one of    inventive concepts 129-142, wherein a proximally-facing surface    defined by the tissue-coupling element is concave when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 177. The apparatus according to any one of    inventive concepts 129-142, wherein a proximally-facing surface    defined by the tissue-coupling element is convex when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 178. The apparatus according to any one of    inventive concepts 129-142,

wherein the tissue anchor is a first tissue anchor, and

wherein the apparatus further comprises:

-   -   a second tissue anchor, which is separate and distinct from the        first tissue anchor; and    -   one or more tethers, which are configured to couple (a) the        first tissue anchor to (b) the second tissue anchor.

-   Inventive concept 179. The apparatus according to inventive concept    178, wherein the one or more tethers are fixed to (a) the first    tissue anchor and (b) the second tissue anchor.

-   Inventive concept 180. The apparatus according to inventive concept    178, wherein the second tissue anchor comprises a helical    tissue-coupling element.

-   Inventive concept 181. The apparatus according to inventive concept    178, wherein the second tissue anchor comprises a stent.

There is additionally provided, in accordance with an inventive concept182 of the present invention, apparatus for delivery in a constrainedstate within a deployment tool, the apparatus comprising:

a first tissue anchor, which comprises (a) a shaft, (b) a head connectedto a proximal portion of the shaft, and (c) a tissue-coupling element,which extends from a distal end of the shaft;

a second tissue anchor, which is separate and distinct from the firsttissue anchor;

one or more tethers, which are configured to couple (a) the first tissueanchor to (b) the second tissue anchor,

wherein, when the tissue anchor is unconstrained by the deployment tool:

-   -   the shaft has a central longitudinal axis,    -   the head is coaxial with the central longitudinal axis, and    -   the tissue-coupling element is shaped such that if the        tissue-coupling element were to be projected onto a plane that        is perpendicular to the central longitudinal axis, (a) at least        80% of an area of a projection of the tissue-coupling element on        the plane would fall within a first angle of 180 degrees in the        plane having a vertex at the central longitudinal axis, and (b)        the area would partially overlap, at least 3 mm from the vertex,        both rays of a second angle of between 45 and 180 degrees in the        plane having the vertex at the central longitudinal axis.

-   Inventive concept 183. The apparatus according to inventive concept    182, wherein the one or more tethers are configured to couple (a)    the head of the first tissue anchor to (b) the second tissue anchor.

-   Inventive concept 184. The apparatus according to inventive concept    183, wherein the one or more tethers are fixed to (a) the head of    the first tissue anchor to (b) the second tissue anchor.

-   Inventive concept 185. The apparatus according to inventive concept    182, wherein at least 95% of the area of the projection of the    tissue-coupling element on the plane would fall within the first    angle.

-   Inventive concept 186. The apparatus according to inventive concept    182, wherein at least 80% of the area of the projection of the    tissue-coupling element on the plane would fall within a third angle    of 150 degrees in the plane having the vertex at the central    longitudinal axis.

-   Inventive concept 187. The apparatus according to inventive concept    182, wherein an outer portion of the area of the projection of the    tissue-coupling element on the plane would fall within all angular    positions of a fourth angle of 90 degrees in the plane having the    vertex at the central longitudinal axis, which outer portion    consists of all points of the area at least 3 mm from the vertex.

-   Inventive concept 188. The apparatus according to inventive concept    182, wherein a proximally-facing surface defined by the    tissue-coupling element is concave when the tissue anchor is    unconstrained by the deployment tool.

-   Inventive concept 189. The apparatus according to inventive concept    182, wherein, when the tissue anchor is unconstrained by the    deployment tool:

a greatest longitudinal dimension of the tissue-coupling element,measured parallel to the central longitudinal axis, is between 1 and 5mm, and

a greatest lateral dimension of the tissue-coupling element, measuredperpendicular to the central longitudinal axis, is between 4 and 20 mm.

-   Inventive concept 190. The apparatus according to inventive concept    189, wherein a ratio of the greatest longitudinal dimension and the    greatest lateral dimension is between 1:2 and 1:18 when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 191. The apparatus according to inventive concept    182, wherein the tissue-coupling element has a length of 5 to 60 mm    when constrained into a straight configuration.-   Inventive concept 192. The apparatus according to inventive concept    182, wherein the tissue-coupling element is non-helical when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 193. The apparatus according to inventive concept    182, wherein the shaft comprises a sealing element.-   Inventive concept 194. The apparatus according to inventive concept    182, wherein the central longitudinal axis is straight when the    first tissue anchor is unconstrained by the deployment tool.-   Inventive concept 195. The apparatus according to inventive concept    182, wherein the shaft is flexible.-   Inventive concept 196. The apparatus according to inventive concept    182, wherein the shaft and the tissue-coupling element are integral    to one another.-   Inventive concept 197. The apparatus according to inventive concept    196, wherein the shaft and the tissue-coupling element comprise a    wire.-   Inventive concept 198. The apparatus according to any one of    inventive concepts 182-197, wherein the tissue-coupling element    comprises at least three tines that extend radially outward from the    central longitudinal axis in respective directions that are fixed    with respect to one another when the tissue anchor is unconstrained    by the deployment tool.-   Inventive concept 199. The apparatus according to inventive concept    198, wherein the tines comprise at least four tines.-   Inventive concept 200. The apparatus according to any one of    inventive concepts 182-197, wherein the tissue-coupling element    comprises a wire.-   Inventive concept 201. The apparatus according to inventive concept    200,

wherein the wire is shaped as an open loop having more than one turn,when the tissue anchor is unconstrained by the deployment tool,

wherein the tissue anchor further comprises a flexible elongate tensionmember, which includes (a) a distal portion that is fixed to a site onthe open loop, (b) a proximal portion, which has a longitudinal segmentthat runs alongside at least a portion of the shaft, and (c) a crossingportion, which (i) is disposed between the distal and the proximalportions along the flexible elongate tension member, and (ii) crosses atleast a portion of the open loop when the tissue anchor is unconstrainedby the deployment tool, and

wherein the tissue anchor is configured to allow relative axial motionbetween the at least a portion of the shaft and the longitudinal segmentof the proximal portion of the flexible elongate tension member when thetissue anchor is unconstrained by the deployment tool.

-   Inventive concept 202. The apparatus according to inventive concept    201,

wherein the head is shaped so as to define a passage in which theproximal portion of the flexible elongate tension member is slidablydisposed,

wherein the flexible elongate tension member comprises a lockingstopper, which is axially fixed to the proximal or the crossing portionof the flexible elongate tension member, and

wherein the locking stopper and the passage are sized and shaped suchthat the size and shape of the passage prevent proximal movement of thelocking stopper past the passage.

-   Inventive concept 203. The apparatus according to inventive concept    201, wherein the open loop is shaped as a spiral when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 204. The apparatus according to inventive concept    203, wherein the spiral is shaped as a three-dimensional spiral when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 205. The apparatus according to inventive concept    203, wherein the spiral is shaped as an elliptical spiral when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 206. The apparatus according to inventive concept    201, wherein the open loop is shaped as a three-dimensional open    loop when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 207. The apparatus according to inventive concept    201, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop surrounds a center point, and

(a) a site distance between the site and the distal end of the shaft isgreater than (b) a center-point distance between the center point andthe distal end of the shaft when the tissue anchor is unconstrained bythe deployment tool.

-   Inventive concept 208. The apparatus according to inventive concept    207, wherein the site distance equals at least 150% of the    center-point distance when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 209. The apparatus according to inventive concept    208, wherein the site distance equals at least 175% of the    center-point distance when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 210. The apparatus according to inventive concept    201, wherein the site is on an outermost turn of the open loop when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 211. The apparatus according to inventive concept    201, wherein the site is on a second-to-outermost turn of the open    loop when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 212. The apparatus according to inventive concept    201, wherein a radius of the flexible elongate tension member is    less than a radius of the wire.-   Inventive concept 213. The apparatus according to inventive concept    212, wherein the radius of the flexible elongate tension member is    less than 50% of the radius of the wire.-   Inventive concept 214. The apparatus according to inventive concept    201, wherein the longitudinal segment of the proximal portion of the    flexible elongate tension member is coupled in sliding communication    with the at least a portion of the shaft when the tissue anchor is    unconstrained by the deployment tool.-   Inventive concept 215. The apparatus according to inventive concept    214, wherein the tissue anchor comprises one or more annular    elements, which are disposed around the at least a portion of the    shaft, and couple the flexible elongate tension member in the    sliding communication with the at least a portion of the shaft when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 216. The apparatus according to inventive concept    201, wherein the flexible elongate tension member is not fixed to    any portion of the open loop beyond 2 mm from the site on the open    loop, measured when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 217. The apparatus according to inventive concept    201, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto the central longitudinal axis, and

the flexible elongate tension member is not fixed to any portion of theopen loop beyond a distance from the site on the open loop, wherein thedistance equals 30% of the greatest lateral dimension.

-   Inventive concept 218. The apparatus according to inventive concept    201, wherein the flexible elongate tension member is fixed to the    open loop only at the site on the open loop.-   Inventive concept 219. The apparatus according to inventive concept    201, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto the central longitudinal axis, and

the at least a portion of the open loop crossed by the crossing portionhas a length that equals at least 50% of the greatest lateral dimension.

-   Inventive concept 220. The apparatus according to inventive concept    219, wherein the length of the at least a portion of the open loop    crossed by the crossing portion equals at least 75% of the greatest    lateral dimension when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 221. The apparatus according to inventive concept    220, wherein the length of the at least a portion of the open loop    crossed by the crossing portion equals at least 90% of the greatest    lateral dimension when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 222. The apparatus according to inventive concept    201, wherein, when the tissue anchor is unconstrained by the    deployment tool and the flexible elongate tension member is    tensioned straight, if the tissue-coupling element and the flexible    elongate tension member were to be projected onto the plane that is    perpendicular to the central longitudinal axis, an angle between (a)    the flexible elongate tension member and (b) a tangent to the open    loop at the site would be between 70 and 90 degrees.-   Inventive concept 223. The apparatus according to inventive concept    201, wherein the site on the open loop is a first site on the open    loop, and wherein, when the tissue anchor is unconstrained by the    deployment tool and the flexible elongate tension member is    tensioned straight:

the open loop surrounds a center point,

the wire extends from the distal end of the shaft at a second site onthe open loop, and

if the tissue-coupling element and the flexible elongate tension memberwere to be projected onto the plane that is perpendicular to the centrallongitudinal axis, a third angle between the first and the second sites,having a vertex at the center point, would be between 130 and 180degrees.

-   Inventive concept 224. The apparatus according to inventive concept    223, wherein the third angle is between 150 and 180 degrees.-   Inventive concept 225. The apparatus according to inventive concept    224, wherein the third angle is between 170 and 180 degrees.-   Inventive concept 226. The apparatus according to inventive concept    223, the second site is at a radially-outer end of the open loop    when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 227. The apparatus according to inventive concept    201, wherein the flexible elongate tension member comprises Nitinol.-   Inventive concept 228. The apparatus according to inventive concept    201, wherein the one or more tethers are configured to couple (a)    the first tissue anchor to (b) the second tissue anchor by    coupling (a) the flexible elongate tension member to (b) the second    tissue anchor.-   Inventive concept 229. The apparatus according to inventive concept    228, wherein the one or more tethers are fixed to (a) the flexible    elongate tension member to (b) the second tissue anchor.-   Inventive concept 230. The apparatus according to inventive concept    201,

further comprising a deployment tool, which comprises a sharp distalpiercing tip, and which is configured to constrain the tissue-couplingelement while delivering the tissue-coupling element through tissue, and

wherein, when the tissue-coupling element is constrained by thedeployment tool, a longitudinal portion of the flexible elongate tensionmember runs alongside a portion of the wire.

-   Inventive concept 231. The apparatus according to inventive concept    200, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the wire of the tissue-coupling element is shaped as an open loop arounda center point having more than one turn, and the wire extends from thedistal end of the shaft at a radially-outer end of the open loop.

-   Inventive concept 232. The apparatus according to inventive concept    231, wherein the open loop is shaped as a spiral when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 233. The apparatus according to inventive concept    232, wherein the spiral is shaped as a three-dimensional spiral when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 234. The apparatus according to inventive concept    232, wherein the spiral is shaped as an elliptical spiral when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 235. The apparatus according to inventive concept    231, wherein the open loop is shaped as a three-dimensional open    loop when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 236. The apparatus according to inventive concept    231, wherein the wire intersects the center point when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 237. The apparatus according to inventive concept    231, wherein the wire does not intersect the center point when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 238. The apparatus according to inventive concept    231, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto the central longitudinal axis, and

a distance between (a) the radially-outer end of the open loop and (b) aradially-inner-most point of the open loop, measured perpendicular tothe central longitudinal axis, is equal to at least 30% of the greatestlateral dimension.

-   Inventive concept 239. The apparatus according to inventive concept    231, wherein a proximally-facing surface defined by the    tissue-coupling element is convex when the tissue anchor is    unconstrained by the deployment tool.-   Inventive concept 240. The apparatus according to inventive concept    200, wherein a cross-sectional area of the wire is at least 0.09    mm2.-   Inventive concept 241. The apparatus according to inventive concept    240, wherein the cross-sectional area of the wire is no more than    2.9 mm2.

There is yet additionally provided, in accordance with an inventiveconcept 242 of the present invention, apparatus for delivery in aconstrained state within a deployment tool, the apparatus comprising atissue anchor, which comprises:

a shaft; and

a tissue-coupling element, which extends from a distal end of the shaft,and which comprises three or more tines,

wherein, when the tissue anchor is unconstrained by the deployment tool:

-   -   the shaft has a central longitudinal axis,    -   the tines extend radially outward from the central longitudinal        axis in respective directions that are fixed with respect to one        another, and    -   the tissue-coupling element is shaped such that if the        tissue-coupling element were to be projected onto a plane that        is perpendicular to the central longitudinal axis, at least 80%        of an area of projected the tissue-coupling element on the plane        would fall within an angle of 210 degrees in the plane having a        vertex at the central longitudinal axis.

-   Inventive concept 243. The apparatus according to inventive concept    242, wherein the three or more tines comprise four or more tines.

-   Inventive concept 244. The apparatus according to inventive concept    242, wherein at least 80% of the area of the projection of the    tissue-coupling element on the plane would fall within a second    angle of 180 degrees in the plane having the vertex at the central    longitudinal axis.

-   Inventive concept 245. The apparatus according to inventive concept    242, wherein, when the tissue anchor is unconstrained by the    deployment tool:

a greatest longitudinal dimension of the tissue-coupling element,measured parallel to the central longitudinal axis, is between 1 and 5mm, and

a greatest lateral dimension of the tissue-coupling element, measuredperpendicular to the central longitudinal axis, is between 4 and 20 mm.

-   Inventive concept 246. The apparatus according to inventive concept    242, wherein the shaft comprises a sealing element.-   Inventive concept 247. The apparatus according to inventive concept    242, wherein the central longitudinal axis is straight when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 248. The apparatus according to inventive concept    242, wherein the shaft is flexible.-   Inventive concept 249. The apparatus according to any one of    inventive concepts 242-248, wherein the tines have respective distal    ends, each of which does not define a sharp distal tip.-   Inventive concept 250. The apparatus according to inventive concept    249, wherein each of the distal ends is blunt.-   Inventive concept 251. The apparatus according to any one of    inventive concepts 242-248, wherein the tissue-coupling element    further comprises one or more membranes that are fixed to and extend    between circumferentially-adjacent ones of the tines.-   Inventive concept 252. The apparatus according to inventive concept    251, wherein a proximally-facing surface defined by the    tissue-coupling element is concave when the tissue anchor is    unconstrained by the deployment tool.-   Inventive concept 253. The apparatus according to inventive concept    251,

wherein the tines are first tines, and wherein the one or more membranesare one or more first membranes that are fixed to and extend betweencircumferentially-adjacent ones of the first tines,

wherein the tissue-coupling element further comprises:

-   -   three or more second tines;    -   one or more second membranes that are fixed to and extend        between circumferentially-adjacent ones of the second tines, and        are not fixed to any of the first tines, and

wherein the first membranes are not fixed to any of the second tines.

-   Inventive concept 254. The apparatus according to inventive concept    253, wherein the tissue anchor is configured such that the second    tines are rotatable with respect to the first tines.-   Inventive concept 255. The apparatus according to inventive concept    254, wherein, when the tissue anchor is unconstrained by the    deployment tool, the tissue-coupling element is shaped such that:

the first membranes extend circumferentially around the centrallongitudinal axis between 90 and 180 degrees, and

the second membranes extend circumferentially around the centrallongitudinal axis between 90 and 180 degrees.

-   Inventive concept 256. The apparatus according to inventive concept    254, wherein, when the tissue anchor is unconstrained by the    deployment tool, the tissue-coupling element is shaped such that:

the first membranes extend circumferentially around the centrallongitudinal axis a first number of degrees,

the second membranes extend circumferentially around the centrallongitudinal axis a second number of degrees, and

a sum of the first and second numbers of degrees is between 100 and 350degrees.

-   Inventive concept 257. The apparatus according to inventive concept    256, wherein the sum is between 150 and 270 degrees.-   Inventive concept 258. The apparatus according to any one of    inventive concepts 242-248,

wherein the tines are first tines, which are rationally fixed withrespect to one another,

wherein the tissue-coupling element further comprises three or moresecond tines, which are rationally fixed with respect to one another,and

wherein the tissue anchor is configured such that the second tines arerotatable with respect to the first tines.

-   Inventive concept 259. The apparatus according to any one of    inventive concepts 242-248,

wherein the tissue anchor is a first tissue anchor, and

wherein the apparatus further comprises:

-   -   a second tissue anchor, which is separate and distinct from the        first tissue anchor; and    -   one or more tethers, which are configured to couple (a) the        first tissue anchor to (b) the second tissue anchor.

-   Inventive concept 260. The apparatus according to inventive concept    259, wherein the one or more tethers are fixed to (a) the first    tissue anchor and (b) the second tissue anchor.

-   Inventive concept 261. The apparatus according to inventive concept    259, wherein the second tissue anchor comprises a helical    tissue-coupling element.

-   Inventive concept 262. The apparatus according to inventive concept    259, wherein the second tissue anchor comprises a stent.

-   Inventive concept 263. The apparatus according to any one of    inventive concepts 242-248, wherein a proximally-facing surface    defined by the tissue-coupling element is concave when the tissue    anchor is unconstrained by the deployment tool.

There is also provided, in accordance with an inventive concept 264 ofthe present invention, a method comprising:

providing a tissue anchor that comprises (a) a shaft, (b) atissue-coupling element, which comprises a wire, and (c) a flexibleelongate tension member;

introducing, during a transcatheter procedure, the tissue anchor into acardiac chamber of a heart of a subject, while the tissue-couplingelement is constrained by a deployment tool;

delivering the tissue-coupling element through a wall of the heart; and

at least partially releasing the tissue anchor from the deployment toolsuch that (a) the tissue-coupling element is unconstrained by thedeployment tool, (b) the wire of the tissue-coupling element is shapedas an open loop having more than one turn, (c) a distal portion of theflexible elongate tension member is fixed to a site on the open loop,(d) a longitudinal segment of a proximal portion of the flexibleelongate tension member runs alongside at least a portion of the shaft,(e) a crossing portion of the flexible elongate tension member, disposedbetween the distal and the proximal portions along the flexible elongatetension member, crosses at least a portion of the open loop, and (f) thetissue anchor allows relative axial motion between the at least aportion of the shaft and the longitudinal segment of the proximalportion of the flexible elongate tension member.

-   Inventive concept 265. The method according to inventive concept    264, further comprising, after delivering the tissue-coupling    element through the wall of the heart, at least partially    compressing the open loop by applying tension to the flexible    elongate tension member.-   Inventive concept 266. The method according to inventive concept    264, further comprising, after delivering the tissue-coupling    element through the wall of the heart, at least partially    compressing the open loop and pulling the tissue-coupling element    against an external surface of the heart, by applying tension to the    flexible elongate tension member.-   Inventive concept 267. The method according to inventive concept    264,

wherein the tissue anchor comprises a head connected to a proximalportion of the shaft,

wherein the head is shaped so as to define a passage in which theproximal portion of the flexible elongate tension member is slidablydisposed,

wherein the flexible elongate tension member comprises a lockingstopper, which is axially fixed to the proximal or the crossing portionof the flexible elongate tension member,

wherein the locking stopper and the passage are sized and shaped suchthat the size and shape of the passage prevent proximal movement of thelocking stopper past the passage, and

wherein the method further comprises, after delivering thetissue-coupling element through the wall of the heart:

-   -   at least partially compressing the open loop by applying tension        to the flexible elongate tension member; and    -   after the passage prevents proximal movement of the locking        stopper past the passage, applying, to the flexible elongate        tension member, additional tension that does not further        compress the open loop.

-   Inventive concept 268. The method according to inventive concept    267, wherein the locking stopper is axially fixed to the proximal or    the crossing portion of the flexible elongate tension member at a    distance of between 7 and 22 mm from the site on the open loop.

-   Inventive concept 269. The method according to inventive concept    267, wherein, if the tissue-coupling element were straightened in an    elongated configuration, the locking stopper would be a distance of    between 7 and 12 mm from the passage.

-   Inventive concept 270. The method according to inventive concept    264, wherein the open loop is shaped as a spiral when the tissue    anchor is unconstrained by the deployment tool.

-   Inventive concept 271. The method according to inventive concept    270, wherein the spiral is shaped as a three-dimensional spiral when    the tissue anchor is unconstrained by the deployment tool.

-   Inventive concept 272. The method according to inventive concept    270, wherein the spiral is shaped as an elliptical spiral when the    tissue anchor is unconstrained by the deployment tool.

-   Inventive concept 273. The method according to inventive concept    264, wherein the open loop is shaped as a three-dimensional open    loop when the tissue anchor is unconstrained by the deployment tool.

-   Inventive concept 274. The method according to inventive concept    273, wherein, when the tissue anchor is unconstrained by the    deployment tool:

a greatest longitudinal dimension of the three-dimensional open loop,measured in parallel to a central longitudinal axis of the shaft, isbetween 1 and 5 mm, and

a greatest lateral dimension of the three-dimensional open loop,measured perpendicular to the central longitudinal axis, is between 4and 20 mm.

-   Inventive concept 275. The method according to inventive concept    264, further comprising, after delivering the tissue-coupling    element through the wall of the heart:

ascertaining whether the tissue-coupling element overlies a coronaryblood vessel; and

if the tissue-coupling element overlies the coronary blood vessel,rotating the tissue anchor until the tissue-coupling element no longeroverlies the coronary blood vessel.

-   Inventive concept 276. The method according to inventive concept    264, further comprising, after delivering the tissue-coupling    element through the wall of the heart:

rotating the tissue anchor by rotating the shaft; and

bringing the tissue-coupling element into contact with an externalsurface of the heart by applying tension to the flexible elongatetension member.

-   Inventive concept 277. The method according to inventive concept    276, wherein bringing the tissue-coupling element into contact with    the external surface of the heart comprises bringing the    tissue-coupling element into contact with the external surface of    the heart without applying any tension to the shaft.-   Inventive concept 278. The method according to inventive concept    264, wherein the site is on an outermost turn of the open loop when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 279. The method according to inventive concept    264, wherein the site is on a second-to-outermost turn of the open    loop when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 280. The method according to inventive concept    264, wherein a radius of the flexible elongate tension member is    less than a radius of the wire.-   Inventive concept 281. The method according to inventive concept    280, wherein the radius of the flexible elongate tension member is    less than 50% of the radius of the wire.-   Inventive concept 282. The method according to inventive concept    264, wherein, when the tissue anchor is unconstrained by the    deployment tool and the flexible elongate tension member is    tensioned straight, if the tissue-coupling element and the flexible    elongate tension member were to be projected onto a plane that is    perpendicular to a central longitudinal axis of the shaft, an angle    between (a) the flexible elongate tension member and (b) a tangent    to the open loop at the site would be between 70 and 90 degrees.-   Inventive concept 283. The method according to inventive concept    264, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop is shaped so as to define an outermost turn and asecond-to-outermost at least partial turn, and

the outermost turn at least partially overlaps the second-to-outermostat least partial turn.

-   Inventive concept 284. The method according to inventive concept    264, wherein, when the tissue anchor is unconstrained by the    deployment tool, the open loop is shaped so as to define one or more    curved segments and one or more straight segments.-   Inventive concept 285. The method according to inventive concept    284, wherein, when the tissue anchor is unconstrained by the    deployment tool, the open loop is shaped so as to define the one or    more curved segments and two or more straight segments.-   Inventive concept 286. The method according to inventive concept    264, wherein the site on the open loop is a first site on the open    loop, and wherein, when the tissue anchor is unconstrained by the    deployment tool and the flexible elongate tension member is    tensioned straight:

the open loop surrounds a center point,

the wire extends from the distal end of the shaft at a second site onthe open loop, and

if the tissue-coupling element and the flexible elongate tension memberwere to be projected onto a plane that is perpendicular to a centrallongitudinal axis of the shaft, an angle between the first and thesecond sites, having a vertex at the center point, would be between 130and 180 degrees.

-   Inventive concept 287. The method according to inventive concept    286, wherein the angle is between 150 and 180 degrees.-   Inventive concept 288. The method according to inventive concept    287, wherein the angle is between 170 and 180 degrees.-   Inventive concept 289. The method according to inventive concept    286, the second site is at a radially-outer end of the open loop    when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 290. The method according to inventive concept    264, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto a central longitudinal axis of the shaft, and

a distance between (a) a radially-outer end of the open loop and (b) aradially-inner-most point of the open loop, measured perpendicular tothe central longitudinal axis, is equal to at least 30% of the greatestlateral dimension.

-   Inventive concept 291. The method according to inventive concept    290, wherein a ratio of the greatest longitudinal dimension and the    greatest lateral dimension is between 1:2 and 1:18 when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 292. The method according to inventive concept    264, wherein the shaft comprises a sealing element.-   Inventive concept 293. The method according to inventive concept    264, wherein the shaft has a central longitudinal axis that is    straight when the tissue anchor is unconstrained by the deployment    tool.-   Inventive concept 294. The method according to inventive concept    264, wherein the shaft is flexible.-   Inventive concept 295. The method according to inventive concept    264, wherein the shaft and the tissue-coupling element are integral    to one another.-   Inventive concept 296. The method according to inventive concept    264, wherein a cross-sectional area of the wire is at least 0.09    mm2.-   Inventive concept 297. The method according to inventive concept    296, wherein the cross-sectional area of the wire is no more than    2.9 mm2.-   Inventive concept 298. The method according to inventive concept    264, wherein the flexible elongate tension member comprises Nitinol.-   Inventive concept 299. The method according to inventive concept    264, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop surrounds a center point, and

(a) a site distance between the site and the distal end of the shaft isgreater than (b) a center-point distance between the center point andthe distal end of the shaft when the tissue anchor is unconstrained bythe deployment tool.

-   Inventive concept 300. The method according to inventive concept    299, wherein the site distance equals at least 150% of the    center-point distance when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 301. The method according to inventive concept    300, wherein the site distance equals at least 175% of the    center-point distance when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 302. The method according to inventive concept    264, wherein the longitudinal segment of the proximal portion of the    flexible elongate tension member is coupled in sliding communication    with the at least a portion of the shaft when the tissue anchor is    unconstrained by the deployment tool.-   Inventive concept 303. The method according to inventive concept    302, wherein the tissue anchor comprises one or more annular    elements, which are disposed around the at least a portion of the    shaft, and couple the flexible elongate tension member in the    sliding communication with the at least a portion of the shaft when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 304. The method according to inventive concept    264, wherein the flexible elongate tension member is not fixed to    any portion of the open loop beyond 2 mm from the site on the open    loop, measured when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 305. The method according to inventive concept    264, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto a central longitudinal axis of the shaft, and

the flexible elongate tension member is not fixed to any portion of theopen loop beyond a distance from the site on the open loop, wherein thedistance equals 30% of the greatest lateral dimension.

-   Inventive concept 306. The method according to inventive concept    264, wherein the flexible elongate tension member is fixed to the    open loop only at the site on the open loop.-   Inventive concept 307. The method according to inventive concept    264, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto a central longitudinal axis of the shaft, and

the at least a portion of the open loop crossed by the crossing portionhas a length that equals at least 50% of the greatest lateral dimension.

-   Inventive concept 308. The method according to inventive concept    307, wherein the length of the at least a portion of the open loop    crossed by the crossing portion equals at least 75% of the greatest    lateral dimension when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 309. The method according to inventive concept    308, wherein the length of the at least a portion of the open loop    crossed by the crossing portion equals at least 90% of the greatest    lateral dimension when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 310. The method according to inventive concept    264, wherein the wire extends from a distal end of the shaft at a    radially-outer end of the open loop when the tissue anchor is    unconstrained by the deployment tool.-   Inventive concept 311. The method according to inventive concept    310, wherein, when the tissue anchor is unconstrained by the    deployment tool, the open loop surrounds a center point, and the    wire intersects the center point.-   Inventive concept 312. The method according to inventive concept    310, wherein, when the tissue anchor is unconstrained by the    deployment tool, the open loop surrounds a center point, and the    wire does not intersect the center point.-   Inventive concept 313. The method according to inventive concept    264, wherein the wire extends from a distal end of the shaft at a    radially-inner end of the open loop when the tissue anchor is    unconstrained by the deployment tool.-   Inventive concept 314. The method according to inventive concept    313,

wherein the flexible elongate tension member is a first flexibleelongate tension member, the distal portion is a first distal portion,the proximal portion is a first proximal portion, the crossing portionis a first crossing portion, the site is a first site, the at least aportion of the open loop is at least a first portion of the open loop,and the longitudinal segment of the flexible elongate tension member isa first longitudinal segment of the first flexible elongate tensionmember,

wherein the tissue anchor comprises a second flexible elongate tensionmember, and

wherein at least partially releasing the tissue anchor comprises atleast partially releasing the tissue anchor such that (a) a seconddistal portion of the second flexible elongate tension member is fixedto a second site on the open loop, different from the first site, (b) asecond longitudinal segment of a second proximal portion of the secondflexible elongate tension member runs alongside at least a portion ofthe shaft, and (c) a second crossing portion of the second flexibleelongate tension member, disposed between the second distal and thesecond proximal portions along the second flexible elongate tensionmember, crosses at least a second portion of the open loop when thetissue anchor is unconstrained by the deployment tool, and (d) thetissue anchor allows relative axial motion between the at least aportion of the shaft and the second longitudinal segment of the secondproximal portion of the second flexible elongate tension member.

-   Inventive concept 315. The method according to inventive concept    314, wherein the first proximal portion of the first flexible    elongate tension member and the second proximal portion of the    second flexible elongate tension member join one another.-   Inventive concept 316. The method according to inventive concept    264, wherein a proximally-facing surface defined by the    tissue-coupling element is concave when the tissue anchor is    unconstrained by the deployment tool.-   Inventive concept 317. The method according to inventive concept    264, wherein a proximally-facing surface defined by the    tissue-coupling element is convex when the tissue anchor is    unconstrained by the deployment tool.-   Inventive concept 318. The method according to inventive concept    264, wherein one or more tethers are fixed to the flexible elongate    tension member.-   Inventive concept 319. The method according to inventive concept    264,

wherein the tissue anchor is a first tissue anchor, and

wherein the method further comprises:

-   -   implanting a second tissue anchor in the subject, which second        tissue anchor is separate and distinct from the first tissue        anchor; and    -   facilitating repair of an atrioventricular valve of the subject        by applying tension to one or more tethers that couple the        flexible elongate tension member to the second tissue anchor.

-   Inventive concept 320. The method according to inventive concept    319, further comprising, before applying the tension, coupling the    flexible elongate tension member to the second tissue anchor using    the one or more tethers.

-   Inventive concept 321. The method according to inventive concept    319, wherein the one or more tethers are fixed to (a) the flexible    elongate tension member and (b) the second tissue anchor.

-   Inventive concept 322. The method according to inventive concept    319, wherein the one or more tethers are (a) fixed to the second    tissue anchor and (b) not fixed to the shaft of the first tissue    anchor.

-   Inventive concept 323. The method according to inventive concept    319, wherein the second tissue anchor comprises a helical    tissue-coupling element.

-   Inventive concept 324. The method according to inventive concept    319, wherein the second tissue anchor comprises a stent.

-   Inventive concept 325. The method according to inventive concept    264,

wherein the tissue anchor is a first tissue anchor, and

wherein the method further comprises:

-   -   implanting a second tissue anchor in the subject, which second        tissue anchor is (a) separate and distinct from the first tissue        anchor, and (b) coupled to the flexible elongate tension member;        and    -   facilitating repair of an atrioventricular valve of the subject        by applying tension to flexible elongate tension member.

-   Inventive concept 326. The method according to inventive concept    325, wherein the flexible elongate tension member is fixed to the    second tissue anchor.

-   Inventive concept 327. The method according to inventive concept    264, wherein introducing comprises introducing the tissue anchor    while the tissue-coupling element is constrained by the deployment    tool, and a longitudinal portion of the flexible elongate tension    member runs alongside a portion of the wire.

There is further provided, in accordance with an inventive concept 328of the present invention, a method comprising:

providing a tissue anchor that comprises (a) a shaft and (b) atissue-coupling element, which comprises a wire;

introducing, during a transcatheter procedure, the tissue anchor into acardiac chamber of a heart of a subject, while the tissue-couplingelement is constrained by a deployment tool;

delivering the tissue-coupling element through a wall of the heart; and

at least partially releasing the tissue anchor from the deployment toolsuch that (a) the tissue-coupling element is unconstrained by thedeployment tool by the deployment tool, (b) the wire of thetissue-coupling element is shaped as an open loop having more than oneturn around a center point, and (c) the wire extends from a distal endof the shaft at a radially-outer end of the open loop.

-   Inventive concept 329. The method according to inventive concept    328, wherein the open loop is shaped as a spiral when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 330. The method according to inventive concept    329, wherein the spiral is shaped as a three-dimensional spiral when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 331. The method according to inventive concept    329, wherein the spiral is shaped as an elliptical spiral when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 332. The method according to inventive concept    328, wherein the open loop is shaped as a three-dimensional open    loop when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 333. The method according to inventive concept    332, wherein, when the tissue anchor is unconstrained by the    deployment tool:

a greatest longitudinal dimension of the three-dimensional open loop,measured in parallel to a central longitudinal axis of the shaft, isbetween 1 and 5 mm, and a greatest lateral dimension of thethree-dimensional open loop, measured perpendicular to the centrallongitudinal axis, is between 4 and 20 mm.

-   Inventive concept 334. The method according to inventive concept    328, further comprising, after delivering the tissue-coupling    element through the wall of the heart:

ascertaining whether the tissue-coupling element overlies a coronaryblood vessel; and

if the tissue-coupling element overlies the coronary blood vessel,rotating the tissue anchor until the tissue-coupling element no longeroverlies the coronary blood vessel.

-   Inventive concept 335. The method according to inventive concept    328, further comprising, after delivering the tissue-coupling    element through the wall of the heart, rotating the tissue anchor    and bringing the tissue-coupling element into contact with an    external surface of the heart.-   Inventive concept 336. The method according to inventive concept    328, wherein the wire intersects the center point when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 337. The method according to inventive concept    328, wherein the wire does not intersect the center point when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 338. The method according to inventive concept    328, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto a central longitudinal axis of the shaft, and

a distance between (a) the radially-outer end of the open loop and (b) aradially-inner-most point of the open loop, measured perpendicular tothe central longitudinal axis, is equal to at least 30% of the greatestlateral dimension.

-   Inventive concept 339. The method according to inventive concept    333, wherein a ratio of the greatest longitudinal dimension and the    greatest lateral dimension is between 1:2 and 1:18 when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 340. The method according to inventive concept    328,

wherein the tissue anchor further comprises a flexible elongate tensionmember, which comprises (a) a distal portion that is fixed to a site onthe open loop, (b) a proximal portion, which has a longitudinal segmentthat runs alongside at least a portion of the shaft, and (c) a crossingportion, which (i) is disposed between the distal and the proximalportions along the flexible elongate tension member, and (ii) crosses atleast a portion of the open loop when the tissue anchor is unconstrainedby the deployment tool, and

wherein the tissue anchor is configured to allow relative axial motionbetween the at least a portion of the shaft and the longitudinal segmentof the proximal portion of the flexible elongate tension member when thetissue anchor is unconstrained by the deployment tool.

-   Inventive concept 341. The method according to inventive concept    340, further comprising, after delivering the tissue-coupling    element through the wall of the heart:

rotating the tissue anchor by rotating the shaft; and

bringing the tissue-coupling element into contact with an externalsurface of the heart by applying tension to the flexible elongatetension member.

-   Inventive concept 342. The method according to inventive concept    341, wherein bringing the tissue-coupling element into contact with    the external surface of the heart comprises bringing the    tissue-coupling element into contact with the external surface of    the heart without applying any tension to the shaft.-   Inventive concept 343. The method according to inventive concept    340, wherein the longitudinal segment of the proximal portion of the    flexible elongate tension member is coupled in sliding communication    with the at least a portion of the shaft when the tissue anchor is    unconstrained by the deployment tool.-   Inventive concept 344. The method according to inventive concept    343, wherein the tissue anchor comprises one or more annular    elements, which are disposed around the at least a portion of the    shaft, and couple the flexible elongate tension member in the    sliding communication with the at least a portion of the shaft when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 345. The method according to inventive concept    340, wherein the site is on an outermost turn of the open loop when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 346. The method according to inventive concept    340, wherein the site is on a second-to-outermost turn of the open    loop when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 347. The method according to inventive concept    340, wherein a radius of the flexible elongate tension member is    less than a radius of the wire.-   Inventive concept 348. The method according to inventive concept    347, wherein the radius of the flexible elongate tension member is    less than 50% of the radius of the wire.-   Inventive concept 349. The method according to inventive concept    340, wherein, when the tissue anchor is unconstrained by the    deployment tool and the flexible elongate tension member is    tensioned straight, if the tissue-coupling element and the flexible    elongate tension member were to be projected onto a plane that is    perpendicular to a central longitudinal axis of the shaft, an angle    between (a) the flexible elongate tension member and (b) a tangent    to the open loop at the site would be between 70 and 90 degrees.-   Inventive concept 350. The method according to inventive concept    340, wherein the site on the open loop is a first site on the open    loop, and wherein, when the tissue anchor is unconstrained by the    deployment tool and the flexible elongate tension member is    tensioned straight:

the wire extends from the distal end of the shaft at a second site onthe open loop, and

if the tissue-coupling element and the flexible elongate tension memberwere to be projected onto a plane that is perpendicular to a centrallongitudinal axis of the shaft, an angle between the first and thesecond sites, having a vertex at the center point, would be between 130and 180 degrees.

-   Inventive concept 351. The method according to inventive concept    350, wherein the angle is between 150 and 180 degrees.-   Inventive concept 352. The method according to inventive concept    351, wherein the angle is between 170 and 180 degrees.-   Inventive concept 353. The method according to inventive concept    350, the second site is at a radially-outer end of the open loop    when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 354. The method according to inventive concept    340, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto a central longitudinal axis of the shaft, and

a distance between (a) a radially-outer end of the open loop and (b) aradially-inner-most point of the open loop, measured perpendicular tothe central longitudinal axis, is equal to at least 30% of the greatestlateral dimension.

-   Inventive concept 355. The method according to inventive concept    340, wherein a cross-sectional area of the wire is at least 0.09    mm2.-   Inventive concept 356. The method according to inventive concept    355, wherein the cross-sectional area of the wire is no more than    2.9 mm2.-   Inventive concept 357. The method according to inventive concept    340, wherein the flexible elongate tension member comprises Nitinol.-   Inventive concept 358. The method according to inventive concept    340, wherein (a) a site distance between the site and the distal end    of the shaft is greater than (b) a center-point distance between the    center point and the distal end of the shaft when the tissue anchor    is unconstrained by the deployment tool.-   Inventive concept 359. The method according to inventive concept    358, wherein the site distance equals at least 150% of the    center-point distance when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 360. The method according to inventive concept    359, wherein the site distance equals at least 175% of the    center-point distance when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 361. The method according to inventive concept    340, wherein the flexible elongate tension member is not fixed to    any portion of the open loop beyond 2 mm from the site on the open    loop, measured when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 362. The method according to inventive concept    340, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto a central longitudinal axis of the shaft, and

the flexible elongate tension member is not fixed to any portion of theopen loop beyond a distance from the site on the open loop, wherein thedistance equals 30% of the greatest lateral dimension.

-   Inventive concept 363. The method according to inventive concept    340, wherein the flexible elongate tension member is fixed to the    open loop only at the site on the open loop.-   Inventive concept 364. The method according to inventive concept    340, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto a central longitudinal axis of the shaft, and

the at least a portion of the open loop crossed by the crossing portionhas a length that equals at least 50% of the greatest lateral dimension.

-   Inventive concept 365. The method according to inventive concept    364, wherein the length of the at least a portion of the open loop    crossed by the crossing portion equals at least 75% of the greatest    lateral dimension when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 366. The method according to inventive concept    365, wherein the length of the at least a portion of the open loop    crossed by the crossing portion equals at least 90% of the greatest    lateral dimension when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 367. The method according to inventive concept    340, wherein one or more tethers are fixed to the flexible elongate    tension member.-   Inventive concept 368. The method according to inventive concept    340,

wherein the tissue anchor is a first tissue anchor, and

wherein the method further comprises:

-   -   implanting a second tissue anchor in the subject, which second        tissue anchor is separate and distinct from the first tissue        anchor; and    -   facilitating repair of an atrioventricular valve of the subject        by applying tension to one or more tethers that couple the        flexible elongate tension member to the second tissue anchor.

-   Inventive concept 369. The method according to inventive concept    368, further comprising, before applying the tension, coupling the    flexible elongate tension member to the second tissue anchor using    the one or more tethers.

-   Inventive concept 370. The method according to inventive concept    368, wherein the one or more tethers are fixed to (a) the flexible    elongate tension member and (b) the second tissue anchor.

-   Inventive concept 371. The method according to inventive concept    368, wherein the second tissue anchor comprises a helical    tissue-coupling element.

-   Inventive concept 372. The method according to inventive concept    368, wherein the second tissue anchor comprises a stent.

-   Inventive concept 373. The method according to inventive concept    340,

wherein the tissue anchor is a first tissue anchor, and

wherein the method further comprises:

-   -   implanting a second tissue anchor in the subject, which second        tissue anchor is (a) separate and distinct from the first tissue        anchor, and (b) coupled to the flexible elongate tension member;        and    -   facilitating repair of an atrioventricular valve of the subject        by applying tension to flexible elongate tension member.

-   Inventive concept 374. The method according to inventive concept    373, wherein the flexible elongate tension member is fixed to the    second tissue anchor.

-   Inventive concept 375. The method according to inventive concept    340, wherein introducing comprises introducing the tissue anchor    while the tissue-coupling element is constrained by the deployment    tool, and a longitudinal portion of the flexible elongate tension    member runs alongside a portion of the wire.

-   Inventive concept 376. The method according to inventive concept    328, wherein a proximally-facing surface defined by the    tissue-coupling element is concave when the tissue anchor is    unconstrained by the deployment tool.

-   Inventive concept 377. The method according to inventive concept    328,

wherein a proximally-facing surface defined by the tissue-couplingelement is convex when the tissue anchor is unconstrained by thedeployment tool, and

wherein the method further comprises bringing the proximally-facingsurface defined by the tissue-coupling element into contact with anexternal surface of the heart.

-   Inventive concept 378. The method according to inventive concept    328,

wherein the tissue anchor is a first tissue anchor, and

wherein the method further comprises:

-   -   implanting a second tissue anchor in the subject, which second        tissue anchor is separate and distinct from the first tissue        anchor; and    -   facilitating repair of an atrioventricular valve of the subject        by applying tension to one or more tethers that couple the first        tissue anchor to the second tissue anchor.

-   Inventive concept 379. The method according to inventive concept    378, further comprising, before applying the tension, coupling the    first tissue anchor to the second tissue anchor using the one or    more tethers.

-   Inventive concept 380. The method according to inventive concept    378, wherein one of the one or more tethers is fixed to one of (a)    the first tissue anchor and (b) the second tissue anchor.

-   Inventive concept 381. The method according to inventive concept    378, wherein the second tissue anchor comprises a helical    tissue-coupling element.

-   Inventive concept 382. The method according to inventive concept    378, wherein the second tissue anchor comprises a stent.

-   Inventive concept 383. The method according to inventive concept    328, wherein the shaft comprises a sealing element.

-   Inventive concept 384. The method according to inventive concept    328, wherein a central longitudinal of the shaft axis is straight    when the tissue anchor is unconstrained by the deployment tool.

-   Inventive concept 385. The method according to inventive concept    328, wherein the shaft is flexible.

-   Inventive concept 386. The method according to inventive concept    328, wherein the shaft and the tissue-coupling element are integral    to one another.

-   Inventive concept 387. The method according to inventive concept    328, wherein delivering the tissue-coupling element through the wall    of the heart comprises advancing a sharp distal piercing tip of the    deployment tool through the wall.

There is still further provided, in accordance with an inventive concept388 of the present invention, a method comprising:

providing a tissue anchor that comprises (a) a shaft, (b) a headconnected to a proximal portion of the shaft, and (c) a tissue-couplingelement, which extends from a distal end of the shaft;

introducing, during a transcatheter procedure, the tissue anchor into acardiac chamber of a heart of a subject, while the tissue-couplingelement is constrained by a deployment tool;

delivering the tissue-coupling element through a wall of the heart byadvancing a sharp distal piercing tip of the deployment tool through thewall; and

at least partially releasing the tissue anchor from the deployment toolsuch that (a) the tissue-coupling element is unconstrained by thedeployment tool, (b) the head is coaxial with a central longitudinalaxis of the shaft, and (c) the tissue-coupling element is shaped suchthat if the tissue-coupling element were to be projected onto a planethat is perpendicular to the central longitudinal axis, (i) at least 80%of an area of a projection of the tissue-coupling element on the planewould fall within a first angle of 180 degrees in the plane having avertex at the central longitudinal axis, and (ii) the area wouldpartially overlap, at least 3 mm from the vertex, both rays of a secondangle of between 45 and 180 degrees in the plane having the vertex atthe central longitudinal axis.

-   Inventive concept 389. The method according to inventive concept    388, further comprising, after delivering the tissue-coupling    element through the wall of the heart:

ascertaining whether the tissue-coupling element overlies a coronaryblood vessel; and

if the tissue-coupling element overlies the coronary blood vessel,rotating the tissue anchor until the tissue-coupling element no longeroverlies the coronary blood vessel.

-   Inventive concept 390. The method according to inventive concept    388, further comprising, after delivering the tissue-coupling    element through the wall of the heart, rotating the tissue anchor    and bringing the tissue-coupling element into contact with an    external surface of the heart.-   Inventive concept 391. The method according to inventive concept    390,

wherein introducing the tissue anchor into the cardiac chamber comprisesintroducing the tissue anchor into an atrium of the heart, and

wherein bringing the tissue-coupling element into contact with theexternal surface of the heart comprises bringing the tissue-couplingelement into contact with an external surface of a ventricle of theheart.

-   Inventive concept 392. The method according to inventive concept    391,

wherein introducing the tissue anchor into the atrium comprisesintroducing the tissue anchor into a right atrium, and

wherein bringing the tissue-coupling element into contact with theexternal surface of the ventricle comprises bringing the tissue-couplingelement into contact with an external surface of a right ventricle.

-   Inventive concept 393. The method according to inventive concept    388, wherein at least 95% of the area of the projection of the    tissue-coupling element on the plane would fall within the first    angle.-   Inventive concept 394. The method according to inventive concept    388, wherein at least 80% of the area of the projection of the    tissue-coupling element on the plane would fall within a second    angle of 150 degrees in the plane having the vertex at the central    longitudinal axis.-   Inventive concept 395. The method according to inventive concept    388, wherein an outer portion of the area of the projection of the    tissue-coupling element on the plane would fall within all angular    positions of a second angle of 90 degrees in the plane having the    vertex at the central longitudinal axis, which outer portion    consists of all points of the area at least 3 mm from the vertex.-   Inventive concept 396. The method according to inventive concept    388, wherein a proximally-facing surface defined by the    tissue-coupling element is concave when the tissue anchor is    unconstrained by the deployment tool.-   Inventive concept 397. The method according to inventive concept    388, wherein, when the tissue anchor is unconstrained by the    deployment tool:

a greatest longitudinal dimension of the tissue-coupling element,measured parallel to the central longitudinal axis, is between 1 and 5mm, and

a greatest lateral dimension of the tissue-coupling element, measuredperpendicular to the central longitudinal axis, is between 4 and 20 mm.

-   Inventive concept 398. The method according to inventive concept    397, wherein a ratio of the greatest longitudinal dimension and the    greatest lateral dimension is between 1:2 and 1:18 when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 399. The method according to inventive concept    388, wherein the tissue-coupling element has a length of 5 to 60 mm    when constrained into a straight configuration.-   Inventive concept 400. The method according to inventive concept    388, wherein the tissue-coupling element is non-helical when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 401. The method according to inventive concept    388, wherein the tissue-coupling element comprises at least three    tines that extend radially outward from the central longitudinal    axis in respective directions that are fixed with respect to one    another when the tissue anchor is unconstrained by the deployment    tool.-   Inventive concept 402. The method according to inventive concept    401, wherein the tines comprise at least four tines.-   Inventive concept 403. The method according to inventive concept    388, wherein the shaft comprises a sealing element.-   Inventive concept 404. The method according to inventive concept    388, wherein the tissue-coupling element comprises a wire.-   Inventive concept 405. The method according to inventive concept    404,

wherein the wire is shaped as an open loop having more than one turnwhen the tissue anchor is unconstrained by the deployment tool,

wherein the tissue anchor further comprises a flexible elongate tensionmember, which includes (a) a distal portion that is fixed to a site onthe open loop, (b) a proximal portion, which has a longitudinal segmentthat runs alongside at least a portion of the shaft, and (c) a crossingportion, which (i) is disposed between the distal and the proximalportions along the flexible elongate tension member, and (ii) crosses atleast a portion of the open loop when the tissue anchor is unconstrainedby the deployment tool, and

wherein the tissue anchor is configured to allow relative axial motionbetween the at least a portion of the shaft and the longitudinal segmentof the proximal portion of the flexible elongate tension member when thetissue anchor is unconstrained by the deployment tool.

-   Inventive concept 406. The method according to inventive concept    405,

wherein the head is shaped so as to define a passage in which theproximal portion of the flexible elongate tension member is slidablydisposed,

wherein the flexible elongate tension member comprises a lockingstopper, which is axially fixed to the proximal or the crossing portionof the flexible elongate tension member, and

wherein the locking stopper and the passage are sized and shaped suchthat the size and shape of the passage prevent proximal movement of thelocking stopper past the passage.

-   Inventive concept 407. The method according to inventive concept    405, wherein the open loop is shaped as a spiral when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 408. The method according to inventive concept    407, wherein the spiral is shaped as a three-dimensional spiral when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 409. The method according to inventive concept    407, wherein the spiral is shaped as an elliptical spiral when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 410. The method according to inventive concept    405, wherein the open loop is shaped as a three-dimensional open    loop when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 411. The method according to inventive concept    405, further comprising, after delivering the tissue-coupling    element through the wall of the heart:

rotating the tissue anchor by rotating the shaft; and

bringing the tissue-coupling element into contact with an externalsurface of the heart by applying tension to the flexible elongatetension member.

-   Inventive concept 412. The method according to inventive concept    411, wherein bringing the tissue-coupling element into contact with    the external surface of the heart comprises bringing the    tissue-coupling element into contact with the external surface of    the heart without applying any tension to the shaft.-   Inventive concept 413. The method according to inventive concept    411, wherein the longitudinal segment of the proximal portion of the    flexible elongate tension member is coupled in sliding communication    with the at least a portion of the shaft when the tissue anchor is    unconstrained by the deployment tool.-   Inventive concept 414. The method according to inventive concept    413, wherein the tissue anchor comprises one or more annular    elements, which are disposed around the at least a portion of the    shaft, and couple the flexible elongate tension member in the    sliding communication with the at least a portion of the shaft when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 415. The method according to inventive concept    405, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop surrounds a center point, and

(a) a site distance between the site and the distal end of the shaft isgreater than (b) a center-point distance between the center point andthe distal end of the shaft when the tissue anchor is unconstrained bythe deployment tool.

-   Inventive concept 416. The method according to inventive concept    415, wherein the site distance equals at least 150% of the    center-point distance when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 417. The method according to inventive concept    416, wherein the site distance equals at least 175% of the    center-point distance when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 418. The method according to inventive concept    405, wherein the site is on an outermost turn of the open loop when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 419. The method according to inventive concept    405, wherein the site is on a second-to-outermost turn of the open    loop when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 420. The method according to inventive concept    405, wherein a radius of the flexible elongate tension member is    less than a radius of the wire.-   Inventive concept 421. The method according to inventive concept    420, wherein the radius of the flexible elongate tension member is    less than 50% of the radius of the wire.-   Inventive concept 422. The method according to inventive concept    405, wherein the flexible elongate tension member is not fixed to    any portion of the open loop beyond 2 mm from the site on the open    loop, measured when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 423. The method according to inventive concept    405, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto the central longitudinal axis, and

the flexible elongate tension member is not fixed to any portion of theopen loop beyond a distance from the site on the open loop, wherein thedistance equals 30% of the greatest lateral dimension.

-   Inventive concept 424. The method according to inventive concept    405, wherein the flexible elongate tension member is fixed to the    open loop only at the site on the open loop.-   Inventive concept 425. The method according to inventive concept    405, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto the central longitudinal axis, and

the at least a portion of the open loop crossed by the crossing portionhas a length that equals at least 50% of the greatest lateral dimension.

-   Inventive concept 426. The method according to inventive concept    425, wherein the length of the at least a portion of the open loop    crossed by the crossing portion equals at least 75% of the greatest    lateral dimension when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 427. The method according to inventive concept    426, wherein the length of the at least a portion of the open loop    crossed by the crossing portion equals at least 90% of the greatest    lateral dimension when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 428. The method according to inventive concept    405, wherein, when the tissue anchor is unconstrained by the    deployment tool and the flexible elongate tension member is    tensioned straight, if the tissue-coupling element and the flexible    elongate tension member were to be projected onto the plane that is    perpendicular to the central longitudinal axis, an angle between (a)    the flexible elongate tension member and (b) a tangent to the open    loop at the site would be between 70 and 90 degrees.-   Inventive concept 429. The method according to inventive concept    405, wherein the site on the open loop is a first site on the open    loop, and wherein, when the tissue anchor is unconstrained by the    deployment tool and the flexible elongate tension member is    tensioned straight:

the open loop surrounds a center point,

the wire extends from the distal end of the shaft at a second site onthe open loop, and

if the tissue-coupling element and the flexible elongate tension memberwere to be projected onto the plane that is perpendicular to the centrallongitudinal axis, a third angle between the first and the second sites,having a vertex at the center point, would be between 130 and 180degrees.

-   Inventive concept 430. The method according to inventive concept    429, wherein the third angle is between 150 and 180 degrees.-   Inventive concept 431. The method according to inventive concept    430, wherein the third angle is between 170 and 180 degrees.-   Inventive concept 432. The method according to inventive concept    429, the second site is at a radially-outer end of the open loop    when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 433. The method according to inventive concept    405, wherein the flexible elongate tension member comprises Nitinol.-   Inventive concept 434. The method according to inventive concept    405, wherein one or more tethers are fixed to the flexible elongate    tension member.-   Inventive concept 435. The method according to inventive concept    405,

wherein the tissue anchor is a first tissue anchor, and

wherein the method further comprises:

-   -   implanting a second tissue anchor in the subject, which second        tissue anchor is separate and distinct from the first tissue        anchor; and    -   facilitating repair of an atrioventricular valve of the subject        by applying tension to one or more tethers that couple the        flexible elongate tension member to the second tissue anchor.

-   Inventive concept 436. The method according to inventive concept    435, further comprising, before applying the tension, coupling the    flexible elongate tension member to the second tissue anchor using    the one or more tethers.

-   Inventive concept 437. The method according to inventive concept    435, wherein the one or more tethers are fixed to (a) the flexible    elongate tension member to (b) the second tissue anchor.

-   Inventive concept 438. The method according to inventive concept    435, wherein the second tissue anchor comprises a helical    tissue-coupling element.

-   Inventive concept 439. The method according to inventive concept    435, wherein the second tissue anchor comprises a stent.

-   Inventive concept 440. The method according to inventive concept    405,

wherein the tissue anchor is a first tissue anchor, and

wherein the method further comprises:

-   -   implanting a second tissue anchor in the subject, which second        tissue anchor is (a) separate and distinct from the first tissue        anchor, and (b) coupled to the flexible elongate tension member;        and    -   facilitating repair of an atrioventricular valve of the subject        by applying tension to flexible elongate tension member.

-   Inventive concept 441. The method according to inventive concept    440, wherein the flexible elongate tension member is fixed to the    second tissue anchor.

-   Inventive concept 442. The method according to inventive concept    405, wherein introducing comprises introducing the tissue anchor    while the tissue-coupling element is constrained by the deployment    tool, and a longitudinal portion of the flexible elongate tension    member runs alongside a portion of the wire.

-   Inventive concept 443. The method according to inventive concept    404, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the wire of the tissue-coupling element is shaped as an open loop havingmore than one turn around a center point, and

the wire extends from the distal end of the shaft at a radially-outerend of the open loop.

-   Inventive concept 444. The method according to inventive concept    443, wherein the open loop is shaped as a spiral when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 445. The method according to inventive concept    444, wherein the spiral is shaped as a three-dimensional spiral when    the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 446. The method according to inventive concept    444, wherein the spiral is shaped as an elliptical spiral when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 447. The method according to inventive concept    443, wherein the open loop is shaped as a three-dimensional open    loop when the tissue anchor is unconstrained by the deployment tool.-   Inventive concept 448. The method according to inventive concept    443, wherein the wire intersects the center point when the tissue    anchor is unconstrained by the deployment tool.-   Inventive concept 449. The method according to inventive concept    443, wherein the wire does not intersect the center point when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 450. The method according to inventive concept    443, wherein, when the tissue anchor is unconstrained by the    deployment tool:

the open loop has a greatest lateral dimension, measured perpendicularto the central longitudinal axis, and

a distance between (a) the radially-outer end of the open loop and (b) aradially-inner-most point of the open loop, measured perpendicular tothe central longitudinal axis, is equal to at least 30% of the greatestlateral dimension.

-   Inventive concept 451. The method according to inventive concept    443,

wherein a proximally-facing surface defined by the tissue-couplingelement is convex when the tissue anchor is unconstrained by thedeployment tool, and

wherein the method further comprises bringing the proximally-facingsurface defined by the tissue-coupling element into contact with anexternal surface of the heart.

-   Inventive concept 452. The method according to inventive concept    404, wherein a cross-sectional area of the wire is at least 0.09    mm2.-   Inventive concept 453. The method according to inventive concept    452, wherein the cross-sectional area of the wire is no more than    2.9 mm2.-   Inventive concept 454. The method according to inventive concept    388, wherein the central longitudinal axis is straight when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 455. The method according to inventive concept    388, wherein the shaft is flexible.-   Inventive concept 456. The method according to inventive concept    388, wherein the shaft and the tissue-coupling element are integral    to one another.-   Inventive concept 457. The method according to inventive concept    456, wherein the shaft and the tissue-coupling element comprise a    wire.-   Inventive concept 458. The method according to inventive concept    388, wherein the deployment tool comprises a hypodermic needle.-   Inventive concept 459. The method according to inventive concept    388,

wherein the tissue anchor is a first tissue anchor, and

wherein the method further comprises:

-   -   implanting a second tissue anchor in the subject, which second        tissue anchor is separate and distinct from the first tissue        anchor; and    -   facilitating repair of an atrioventricular valve of the subject        by applying tension to one or more tethers that couple the first        tissue anchor to the second tissue anchor.

-   Inventive concept 460. The method according to inventive concept    459, wherein facilitating repair comprises facilitating repair of    the atrioventricular valve by applying the tension to the one or    more tethers that couple the head of the first tissue anchor to the    second tissue anchor.

-   Inventive concept 461. The method according to inventive concept    459, further comprising, before applying the tension, coupling the    first tissue anchor to the second tissue anchor using the one or    more tethers.

-   Inventive concept 462. The method according to inventive concept    459, wherein one of the one or more tethers is fixed to one of (a)    the first tissue anchor to (b) the second tissue anchor.

-   Inventive concept 463. The method according to inventive concept    459, wherein the second tissue anchor comprises a helical    tissue-coupling element.

-   Inventive concept 464. The method according to inventive concept    459, wherein the second tissue anchor comprises a stent.

There is additionally provided, in accordance with an inventive concept465 of the present invention, a method comprising:

providing a tissue anchor that comprises (a) a shaft and (b) atissue-coupling element, which extends from a distal end of the shaft,and which comprises three or more tines;

introducing, during a transcatheter procedure, the tissue anchor into acardiac chamber of a heart of a subject, while the tissue-couplingelement is constrained by a deployment tool;

delivering the tissue-coupling element through a wall of the heart; and

at least partially releasing the tissue anchor from the deployment toolsuch that (a) the tissue-coupling element is unconstrained by thedeployment tool, (b) the tines extend radially outward from a centrallongitudinal axis of the shaft in respective directions that are fixedwith respect to one another, and (c) the tissue-coupling element isshaped such that if the tissue-coupling element were to be projectedonto a plane that is perpendicular to the central longitudinal axis, atleast 80% of an area of the projection of the tissue-coupling element onthe plane would fall within an angle of 210 degrees in the plane havinga vertex at the central longitudinal axis.

-   Inventive concept 466. The method according to inventive concept    465, further comprising:

ascertaining whether the tissue-coupling element overlies a coronaryblood vessel; and

if the tissue-coupling element overlies the coronary blood vessel,rotating the tissue anchor until the tissue-coupling element no longeroverlies the coronary blood vessel.

-   Inventive concept 467. The method according to inventive concept    465, further comprising, after delivering the tissue-coupling    element through the wall of the heart, rotating the tissue anchor    and bringing the tissue-coupling element into contact with an    external surface of the heart.-   Inventive concept 468. The method according to inventive concept    465, wherein the three or more tines comprise four or more tines.-   Inventive concept 469. The method according to inventive concept    465, wherein at least 80% of the area of the projection of the    tissue-coupling element on the plane would fall within a second    angle of 180 degrees in the plane having the vertex at the central    longitudinal axis.-   Inventive concept 470. The method according to inventive concept    465, wherein the tissue-coupling element further comprises one or    more membranes that are fixed to and extend between    circumferentially-adjacent ones of the tines.-   Inventive concept 471. The method according to inventive concept    470,

wherein the tines are first tines, and wherein the one or more membranesare one or more first membranes that are fixed to and extend betweencircumferentially-adjacent ones of the first tines,

wherein the tissue-coupling element further comprises:

-   -   three or more second tines;    -   one or more second membranes that are fixed to and extend        between circumferentially-adjacent ones of the second tines, and        are not fixed to any of the first tines, and

wherein the first membranes are not fixed to any of the second tines.

-   Inventive concept 472. The method according to inventive concept    471, wherein the tissue anchor is configured such that the second    tines are rotatable with respect to the first tines, and wherein the    method further comprises rotating the second tines with respect to    the first tines.-   Inventive concept 473. The method according to inventive concept    472, wherein rotating the second tines with respect to the first    tines comprises setting a level of circumferential overlap of the    second membranes with the first membranes.-   Inventive concept 474. The method according to inventive concept    473,

wherein delivering the tissue-coupling element through the wallcomprises delivering the tissue-coupling element through the wall in avicinity of a coronary blood vessel, and

wherein setting the level of circumferential overlap comprises avoidingcontacting the coronary blood vessel with the tissue-coupling element bysetting the level of circumferential overlap.

-   Inventive concept 475. The method according to inventive concept    473, wherein setting the level of circumferential overlap comprises    setting the level of circumferential overlap such that the first and    the second membranes together extend circumferentially around the    central longitudinal axis by between 100 and 350 degrees.-   Inventive concept 476. The method according to inventive concept    475, wherein setting the level of circumferential overlap comprises    setting the level of circumferential overlap such that the first and    the second membranes together extend circumferentially around the    central longitudinal axis by between 150 and 270 degrees.-   Inventive concept 477. The method according to inventive concept    473, wherein, when the tissue anchor is unconstrained by the    deployment tool, the tissue-coupling element is shaped such that (a)    the first membranes extend circumferentially around the central    longitudinal axis between 90 and 180 degrees, and (b) the second    membranes extend circumferentially around the central longitudinal    axis between 90 and 180 degrees.-   Inventive concept 478. The method according to inventive concept    465,

wherein the tines are first tines, which are rationally fixed withrespect to one another,

wherein the tissue-coupling element further comprises three or moresecond tines, which are rationally fixed with respect to one another,

wherein the tissue anchor is configured such that the second tines arerotatable with respect to the first tines, and

wherein the method further comprises rotating the second tines withrespect to the first tines.

-   Inventive concept 479. The method according to inventive concept    465,

wherein the tissue anchor is a first tissue anchor, and

wherein the method further comprises:

-   -   implanting a second tissue anchor in the subject, which second        tissue anchor is separate and distinct from the first tissue        anchor; and    -   facilitating repair of an atrioventricular valve of the subject        by applying tension to one or more tethers that couple the first        tissue anchor to the second tissue anchor.

-   Inventive concept 480. The method according to inventive concept    479, further comprising, before applying the tension, coupling the    first tissue anchor to the second tissue anchor using the one or    more tethers.

-   Inventive concept 481. The method according to inventive concept    479, wherein one of the one or more tethers is fixed to one of (a)    the first tissue anchor and (b) the second tissue anchor.

-   Inventive concept 482. The method according to inventive concept    479, wherein the second tissue anchor comprises a helical    tissue-coupling element.

-   Inventive concept 483. The method according to inventive concept    479, wherein the second tissue anchor comprises a stent.

-   Inventive concept 484. The method according to inventive concept    465, wherein a proximally-facing surface defined by the    tissue-coupling element is concave when the tissue anchor is    unconstrained by the deployment tool.

-   Inventive concept 485. The method according to inventive concept    465, wherein, when the tissue anchor is unconstrained by the    deployment tool:

a greatest longitudinal dimension of the tissue-coupling element,measured parallel to the central longitudinal axis, is between 1 and 5mm, and

a greatest lateral dimension of the tissue-coupling element, measuredperpendicular to the central longitudinal axis, is between 4 and 20 mm.

-   Inventive concept 486. The method according to inventive concept    465, wherein the shaft comprises a sealing element.-   Inventive concept 487. The method according to inventive concept    465, wherein the central longitudinal axis is straight when the    tissue anchor is unconstrained by the deployment tool.-   Inventive concept 488. The method according to inventive concept    465, wherein the shaft is flexible.

There is yet additionally provided, in accordance with an inventiveconcept 489 of the present invention, apparatus for delivery in aconstrained state within a deployment tool, the apparatus comprising atissue anchor, which comprises:

a shaft having a central longitudinal axis;

a tissue-coupling element, which comprises a wire, wherein when thetissue anchor is unconstrained by the deployment tool: (a) the wire isshaped as an open shape, and (b) if the tissue-coupling element were tobe projected onto a plane that is perpendicular to the centrallongitudinal axis, the open shape would surround between 170 and 355degrees of a point in the plane; and

a flexible elongate tension member, which includes (a) a distal portionthat is fixed to a site on the wire, (b) a proximal portion, which has alongitudinal segment that runs alongside at least a portion of theshaft, and (c) a crossing portion, which (i) is disposed between thedistal and the proximal portions along the flexible elongate tensionmember, and (ii) crosses at least a portion of the open shape when thetissue anchor is unconstrained by the deployment tool,

wherein the tissue anchor is configured to allow relative axial motionbetween the at least a portion of the shaft and the longitudinal segmentof the proximal portion of the flexible elongate tension member when thetissue anchor is unconstrained by the deployment tool.

-   Inventive concept 490. The apparatus according to inventive concept    489,

wherein the tissue anchor comprises a head connected to a proximalportion of the shaft,

wherein the head is shaped so as to define a passage in which theproximal portion of the flexible elongate tension member is slidablydisposed,

wherein the flexible elongate tension member comprises a lockingstopper, which is axially fixed to the proximal or the crossing portionof the flexible elongate tension member, and

wherein the locking stopper and the passage are sized and shaped suchthat the size and shape of the passage prevent proximal movement of thelocking stopper past the passage.

-   Inventive concept 491. The apparatus according to inventive concept    489, wherein the open shape is shaped as a portion of a circle or a    portion of an ellipse when the tissue anchor is unconstrained by the    deployment tool.-   Inventive concept 492. The apparatus according to inventive concept    489, wherein the site on the wire is at a distal end of the wire.-   Inventive concept 493. The apparatus according to inventive concept    492, wherein the wire is shaped so as to define a channel, through    which a portion of the flexible elongate tension member passes and    exits the wire at the distal end of the wire.

The present invention will be more fully understood from the followingdetailed description of embodiments thereof, taken together with thedrawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-D are schematic illustrations of a tissue anchor in severalstages of deployment from a deployment tool, in accordance with anapplication of the present invention;

FIGS. 2A-B and 2C are schematic illustrations of a tissue-couplingelement and a shaft of the tissue anchor of FIGS. 1A-D, in accordancewith respective applications of the present invention;

FIGS. 3A-B are schematic illustrations of the tissue-coupling elementand the shaft of the tissue anchor of FIGS. 1A-D, in accordance withrespective applications of the present invention;

FIGS. 4A-B are schematic illustrations of two configurations of a tissueanchor system, in accordance with respective applications of the presentinvention;

FIGS. 5A-D are schematic illustrations of another tissue anchor inseveral stages of deployment from a deployment tool, in accordance withan application of the present invention;

FIGS. 6A-B are schematic illustrations of two configurations of anothertissue anchor system, in accordance with respective applications of thepresent invention;

FIGS. 7A-B are schematic illustrations of an open loop of the tissueanchor of FIGS. 5A-D unconstrained and under tension, respectively, inaccordance with an application of the present invention;

FIGS. 8A and 8B are schematic illustrations of two configurations of yetanother tissue anchor, in accordance with respective applications of thepresent invention;

FIGS. 9A-D are schematic illustrations of another tissue anchor, inaccordance with an application of the present invention;

FIGS. 9E and 9F are schematic illustrations of alternative ways to fix aflexible elongate tension member to a site of an open loop of the tissueanchor of FIGS. 9A-D, in accordance with respective applications of thepresent invention;

FIG. 9G is a schematic illustration of the anchor of FIGS. 9A-Dcomprising a sealing element, in accordance with an application of thepresent invention;

FIG. 9H is a schematic illustration of another tissue anchor, inaccordance with an application of the present invention;

FIG. 9I is a schematic illustration of another configuration of an openloop, in accordance with an application of the present invention;

FIGS. 10A-B are schematic illustrations of another tissue anchor inseveral stages of deployment from a deployment tool, in accordance withan application of the present invention;

FIGS. 11A-C are schematic illustrations of several views of yet anothertissue anchor, in accordance with an application of the presentinvention;

FIGS. 12A-C are schematic illustrations of still another tissue anchor,in accordance with an application of the present invention;

FIGS. 13A-D are schematic illustrations of a method for deploying thetissue anchor system of FIGS. 4A-B for repairing a tricuspid valve, inaccordance with an application of the present invention;

FIGS. 14A-D are schematic illustrations of a method for deploying thetissue anchor system of FIGS. 6A-B for repairing a tricuspid valve, inaccordance with an application of the present invention;

FIGS. 15A-C are schematic illustrations of another method for deployinga tissue anchor system for repairing the tricuspid valve, in accordancewith an application of the present invention;

FIG. 16 is a schematic illustration of several external exit sites on aheart, in accordance with respective applications of the presentinvention;

FIGS. 17A-F are schematic illustrations of a tissue-anchor system in anunlocked state, in accordance with an application of the presentinvention; and

FIGS. 18A-B are schematic illustrations of the tissue-anchor system ofFIGS. 17A-F in a locked state, in accordance with an application of thepresent invention.

DETAILED DESCRIPTION OF APPLICATIONS

Some embodiments of the present invention provide a tissue anchor 20 anda deployment tool 30, which is typically configured to deliver thetissue anchor through a wall of a heart of a subject, typically byadvancing a sharp distal piercing tip 32 of the deployment tool throughthe wall.

FIGS. 1A-D are schematic illustrations of a tissue anchor 120 in severalstages of deployment from deployment tool 30, in accordance with anapplication of the present invention. Tissue anchor 120 is oneimplementation of tissue anchor 20, described above. Tissue anchor 120comprises (a) a shaft 122, (b) a head 124 connected to a proximalportion 126 of shaft 122, and (c) a tissue-coupling element 128, whichextends from a distal end 130 of shaft 122. For some applications, shaft122 and tissue-coupling element 128 are integral to one another; forexample, shaft 122 and tissue-coupling element 128 may comprise a wire.For some applications, one or more tethers 132 are provided, which areconfigured to be coupled to tissue anchor 120, such as to head 124 oftissue anchor 120; for example, one of the one or more tethers 132 maybe fixed to head 124.

Deployment tool 30 is configured to constrain tissue-coupling element128 while delivering tissue-coupling element 128 through tissue.Typically, during delivery, such as shown in FIG. 1A, deployment tool 30is configured to hold tissue-coupling element 128 in an elongatedconfiguration, which may be straight (such as shown) or curvy (such asshown in FIG. 5A). For some applications, deployment tool 30 comprises ashaft 34 shaped so as to define a lumen, such as a hypodermic needle.The lumen is sized to hold tissue-coupling element 128 constrainedtherein, and, optionally, to hold other portions of tissue anchor 20therein, such as shaft 122 and/or head 124. For some applications,deployment tool 30 has a length of between 100 and 180 cm, and/or aninner diameter of between 2 and 6 mm. For some applications, deploymenttool 30 comprises a distal-most rigid portion, which typically has alength of 5 to 25 mm, and the remaining proximal portion of thedeployment tool is flexible (but not extendable or compressible). Forsome applications, the proximal portion is shaped so as to define one ormore lateral slots, which provide flexibility to the proximal portion,while maintaining a backbone that prevents longitudinal compression andextension of the proximal portion. Typically, deployment tool 30 isadvanced within a steerable catheter tube 40, as is known in the art,which may, for example, comprise a braided material. Typically, tissueanchor 20 is provided in sterile packaging, optionally pre-positioned indeployment tool 30.

FIG. 1A shows tissue anchor 120 (including tissue-coupling element 128,shaft 122, and head 124) fully constrained by deployment tool 30. Whentissue anchor 120 is fully constrained by deployment tool 30,tissue-coupling element 128 typically has an outer diameter of at least0.3 mm, no more than 4 mm, and/or between 0.3 and 4 mm, such as at least1 mm, no more than 3 mm, and/or between 1 and 3 mm.

FIG. 1B shows tissue-coupling element 128 released from deployment tool30, while a portion of tissue anchor 120 is still constrained bydeployment tool 30.

FIG. 1C shows tissue anchor 120 entirely released from deployment tool30.

FIG. 1D shows tissue anchor 120 deployed against a wall 194 of a heartchamber, upon release from deployment tool 30. Tissue-coupling element128 is disposed on a far side of wall 194, and head 124 is disposed on anear side of wall 194.

Reference is now made to FIGS. 2A-B and 2C, which are schematicillustrations of tissue-coupling element 128 and shaft 122, inaccordance with respective applications of the present invention. FIGS.2A-B provide two views of a first configuration tissue-coupling element128 and shaft 122, when tissue anchor 120 is unconstrained by deploymenttool 30, and FIG. 2C provides a view of a second configuration oftissue-coupling element 128 and shaft 122, when tissue anchor 120 isunconstrained by deployment tool 30.

Reference is made to FIGS. 1B-C and 2A-C. When tissue anchor 120 isunconstrained by deployment tool 30, such as shown in FIGS. 1B-C and2A-C:

-   -   shaft 122 has a central longitudinal axis 134,    -   head 124 is coaxial with central longitudinal axis 134, and    -   tissue-coupling element 128 is shaped such that if        tissue-coupling element 128 were to be projected onto a plane        136 that is perpendicular to central longitudinal axis 134:        -   at least 80% (e.g., at least 90%, such as at least 95%) of            an area 138 of a projection 139 of tissue-coupling element            128 on plane 136 would fall within a first angle a (alpha)            of 180 degrees in plane 136 having a vertex 140 at central            longitudinal axis 134, as labeled in FIG. 2B, and        -   area 138 would partially overlap, at a distance D1 of at            least 3 mm from vertex 140, both rays 142A and 142B of a            second angle β (beta) of between 45 and 180 degrees in plane            136 having vertex 140 at central longitudinal axis 134 (the            partial overlap is illustrated by the heavier portions of            the rays).

As used in the present application, including in the claims, a “centrallongitudinal axis” of an elongate structure is the set of all centroidsof transverse cross-sectional sections of the structure along thestructure. Thus the cross-sectional sections are locally perpendicularto the central longitudinal axis, which runs along the structure. (Ifthe structure is circular in cross-section, the centroids correspondwith the centers of the circular cross-sectional sections.)

Tissue-coupling element 128 is configured to have a predetermined shapewhen unconstrained by deployment tool 30. For example, thetissue-coupling element may comprise a shape-memory material, such as ashape-memory alloy, e.g., Nitinol. Thus, tissue-coupling element 128automatically transitions to the predetermined shape when released frombeing constrained by deployment tool 30 to being unconstrained bydeployment tool 30.

For some applications, central longitudinal axis 134 is straight whentissue anchor 120 is unconstrained by deployment tool 30, such as shownin FIGS. 1B-C and 2A-C. For some applications, shaft 122 is flexible.

For some applications, such as shown in FIGS. 1B-C and 2A-B, aproximally-facing surface defined by tissue-coupling element 128 (i.e.,the surface defined by tissue-coupling element 128 that is configured totouch the external surface of the heart) is concave when tissue anchor120 is unconstrained by deployment tool 30 (in other words,tissue-coupling element 128 is concave when viewed from proximal portion126 of shaft 122). Such a concave shape may approximate the naturalconvex shape of an external surface of the wall of the heart.

For other applications, such as shown in FIG. 2C, the proximally-facingsurface defined by tissue-coupling element 128 is convex, when tissueanchor 120 is unconstrained by deployment tool 30 before being pulledagainst the external surface of the heart (in other words,tissue-coupling element 128 is convex when viewed from proximal portion126 of shaft 122). Such a convex shape may be employed such that theradially internal section of the coil closest to a center point 162 oftissue-coupling element 128 contacts the tissue first, and gradually, astension is applied, the full tissue-coupling element comes into contactwith the external surface of the heart. Optionally, upon coming intofull contact with the external surface of the heart, theproximally-facing surface defined by the tissue-coupling element mayassume a concave shape conforming to the convex shape of the externalsurface of the heart. This arrangement may lead to a more evendistribution of load on the heart tissue and result in a more durableloading configuration on the tissue.

For still other applications, the proximally-facing surface defined bytissue-coupling element 128 is generally flat, when tissue anchor 120 isunconstrained by deployment tool 30 (configuration not shown).Optionally, upon coming into full contact with the external surface ofthe heart, the proximally-facing surface defined by the tissue-couplingelement may assume a concave shape conforming to the convex shape of theexternal surface of the heart.

For some applications, when tissue anchor 120 is unconstrained bydeployment tool 30:

-   -   a greatest longitudinal dimension D2 of tissue-coupling element        128, measured parallel to central longitudinal axis 134, is        between 1 and 6 mm (such as between 2 and 5 mm) (labeled in FIG.        2B), and    -   a greatest lateral dimension D3 of tissue-coupling element 128,        measured perpendicular to central longitudinal axis 134, is        between 4 and 25 mm (such as between 5 and 20 mm) (labeled in        FIG. 2A).

Typically, a ratio of the greatest longitudinal dimension D2 andgreatest lateral dimension D3 is between 1:2 and 1:18, such as between1:5 and 1:10, e.g., 1:7 when tissue anchor 120 is unconstrained bydeployment tool 30.

For some applications, tissue-coupling element 128 has a length L of atleast 5 mm (e.g., at least 10 mm), no more than 100 mm (e.g., no morethan 60 mm), and/or between 5 and 100 mm (e.g., between 10 and 60 mm)when constrained into a straight configuration, such as shown in FIG.1A.

For some applications, tissue-coupling element 128 comprises a wire 150.For some applications, a cross-sectional area of wire 150 is at least0.09 mm2 (such as at least 0.18 mm2), no more than 3 mm2 (e.g., no morethan 2.9 mm2), and/or between 0.09 mm2 (such as 0.18 mm2) and 3 mm2(e.g., 2.9 mm2). For some applications, wire 150 has a circularcross-section, and a diameter of wire 150 is at least 0.18 mm, no morethan 2 mm, and/or between 0.18 and 2 mm. For some applications, a distalend 152 of wire 150 does not define a sharp distal tip; for example, thedistal end may be blunt. For some applications, wire 150 comprisesmetal, such as Nitinol. For some applications, wire 150 comprises one ormore radiopaque markers.

For some applications, when tissue anchor 120 is unconstrained bydeployment tool 30, such as shown in FIGS. 1B-C and 2A-C, wire 150 (a)is shaped as an open loop 154 having more than one turn, such that afirst complete turn of open loop 154 at least partially overlaps (i.e.,runs alongside, above, and/or below) a second at-least-partial turn ofopen loop 154. For some applications, the first complete turn and thesecond at-least-partial turn radially coincide, i.e., are at a samedistance as each other from a center point (configuration not shown).For other applications, as shown in the figures, an outermost turn ofopen loop 154 at least partially overlaps (i.e., runs alongside, above,and/or below) a second-to-outermost turn of open loop 154 (for example,an outermost turn 214 and a second-to-outermost turn 216 of open loop154 are labeled in FIG. 5D). (As used in the present application,including in the claims, one turn equals 360 degrees. As used in thepresent application, including in the claims, “more than one turn”should not be understood as requiring at least two turns; instead, “morethan one turn” also includes one turn plus a fraction of a turn, asdescribed below. For example, for applications in which open loop 154includes an outermost turn and a second-to-outermost turn, thesecond-to-outermost turn of open loop 154 may be a partial turn, such asshown in FIGS. 9A-B, 9E, 9F, and 9I.)

For applications in which open loop 154 includes an outermost turn and asecond-to-outermost turn, open loop 154 has a radially-outer end 164 anda radially-inner end 264, which typically do not touch each other atleast when tissue anchor 120 is unconstrained by deployment tool 30. Forapplications in which the first complete turn and the secondat-least-partial turn radially coincide, the two opposite ends of theopen loop typically do not touch each other at least when tissue anchor120 is unconstrained by deployment tool 30. Open loop 154 is defined byan elongate path of wire 150 that winds more than one turn around centerpoint 162 without forming a closed loop. The elongate path may includeone or more curved segments and/or one or more straight segments, suchas described hereinbelow with reference to FIG. 9I. The path may fall intwo dimensions, or may fall in three dimensions, in which case the openloop is a three-dimensional open loop, the elongate path of which windsaround a center axis while moving parallel to the axis, without forminga closed loop.

For some applications, open loop 154 extends from distal end 130 ofshaft 122 at radially-outer end 164 of open loop 154. For someapplications, wire 150 intersects center point 162 when tissue anchor120 is unconstrained by deployment tool 30 (configuration not shown),while for other applications, wire 150 does not intersect center point162 when tissue anchor 120 is unconstrained by deployment tool 30 (asshown).

For some applications, such as shown in FIGS. 1B, 2A-C, 3A-B, 4B, 9A-B,and 9E-G, when tissue anchor 120 is unconstrained by deployment tool 30,open loop 154 has more than one turn and less than two turns. Forexample, as shown in FIGS. 1B, 2A-C, 3A-B, and 4B, open loop 154 mayhave at least 1.5 turns and no more than two turns, or, as shown inFIGS. 9A-B, and 9E-G, open loop 154 may have more than one turn and lessthan 1.5 turns, such as more than one turn, e.g., more than 1.01 turns(363.6 degrees), such as more than 1.02 turns (367.2 degrees), and/orless than 1.25 turns (450 degrees). For other applications, such asshown in FIGS. 5B-D, 6A-B, 7A-B, and 8A-B, open loop 154 may have atleast two turns, such as at least two turns and less than 2.5 turns (asshown in FIGS. 5B-D and 6A-B), or more than 2.5 turns, e.g., more thanthree turns (configurations not shown).

For some applications, when tissue anchor 120 is unconstrained bydeployment tool 30, such as shown in FIGS. 1B-C and 2A-C, wire 150 ofopen loop 154 is shaped as a spiral 160 (e.g., a three-dimensionalspiral) around center point 162. For some of these applications, wire150 of spiral 160 extends from distal end 130 of shaft 122 atradially-outer end 164 of spiral 160. For some applications, wire 150 ofspiral 160 intersects center point 162 when tissue anchor 120 isunconstrained by deployment tool 30 (configuration not shown), while forother applications, wire 150 of spiral 160 does not intersect centerpoint 162 when tissue anchor 120 is unconstrained by deployment tool 30(as shown). For some applications, spiral 160 is generally circular whentissue anchor 120 is unconstrained by deployment tool 30, such as shownin FIGS. 1B, 2A-C, and 3A-B, while for other applications, spiral 160 isan elliptical spiral when the tissue anchor is unconstrained bydeployment tool 30, such as shown in FIGS. 5B-D, 6A-B, 7A, 8A, 9A-B, and9E-G.

As used in the present application, including in the claims, centerpoint 162 is the centroid of projection 139 of tissue-coupling element128 on plane 136. Typically, such as when tissue-coupling element 128 isshaped as a spiral, tissue-coupling element 128 is non-helical whentissue anchor 120 is unconstrained by deployment tool 30.

For some applications, such as shown in FIGS. 1B, 2A-C, 3A-B, 4B, 9A-B,and 9E-G, when the tissue anchor is unconstrained by deployment tool 30,spiral 160 has more than one turn and less than two turns. For example,as shown in FIGS. 1B, 2A-C, 3A-B, and 4B, spiral 160 may have at least1.5 turns and no more than two turns, or, as shown in FIGS. 9A-B and9E-G, spiral 160 may have more than one turn and less than 1.5 turns,such as more than one turn and less than 1.25 turns. For otherapplications, such as shown in FIGS. 5B-D, 6A-B, 7A-B, and 8A-B, spiral160 may have at least two turns, such as at least two turns and lessthan 2.5 turns (as shown in FIGS. 5B-D and 6A-B), or more than 2.5turns, e.g., more than three turns (configurations not shown).

For some applications, as labeled in FIG. 2A, when tissue anchor 120 isunconstrained by deployment tool 30, the open loop (e.g., the spiral)has greatest lateral dimension D3, measured perpendicular to centrallongitudinal axis 134, and a distance D4 between (a) radially-outer end164 of open loop 154 (e.g., spiral 160) and (b) a radially-inner-mostpoint 166 of open loop 154 (e.g., spiral 160), measured perpendicular tocentral longitudinal axis 134, is equal to at least 30% of the greatestlateral dimension D3. Alternatively or additionally, for someapplications, a distance between radially-inner-most point 166 and aclosest point thereto on an outermost turn of open loop 154, measuredperpendicular to central longitudinal axis 134, is equal to at least 30%of the greatest lateral dimension D3. For other applications, such asthose described hereinbelow with reference to FIGS. 9A-B and 9E-G, adistance between radially-inner-most point 166 and a closest pointthereto on an outermost turn of open loop 154, measured perpendicular tocentral longitudinal axis 134, equals less than 10% of the greatestlateral dimension D3.

Reference is made to FIGS. 3A-B, which are schematic illustrations oftissue-coupling element 128 and shaft 122, in accordance with respectiveapplications of the present invention. For some applications, as shownin FIG. 3A, at least 80%, such as at least 90%, e.g., at least 95%, ofarea 138 of projection 139 of tissue-coupling element 128 on plane 136would fall within a third angle y (gamma) of 150 degrees in plane 136having vertex 140 at central longitudinal axis 134, if tissue-couplingelement 128 were to be projected onto plane 136.

For some applications, as shown in FIG. 3B, an outer portion 168 of area138 of projection 139 of tissue-coupling element 128 on plane 136consists of all points of area 138 at least a distance D from vertex140; for example, the distance D may be 2 mm, such as 3 mm, e.g., 4 mm.Outer portion 168 would fall within all angular positions of a fourthangle δ (delta) of 90 degrees in plane 136 having vertex 140 at centrallongitudinal axis 134, which outer portion 168, if tissue-couplingelement 128 were to be projected onto plane 136. In other words, at allangular positions of fourth angle δ (delta), there is at least one pointof outer portion 168. (Outer portion 168 may additionally fall withinangular positions outside of fourth angle δ (delta), such as shown inFIG. 3B.)

Reference is now made to FIGS. 4A-B, which are schematic illustrationsof two configurations of a tissue anchor system 180, in accordance withrespective applications of the present invention. In these applications,tissue anchor 120 is a first tissue anchor 182A of tissue anchor system180, which further comprises (a) a second tissue anchor 182B, which isseparate and distinct first tissue anchor 182A, and (b) the one or moretethers 132, which are configured to couple (i) head 124 of first tissueanchor 182A to (ii) second tissue anchor 182B. For some applications,one of the one or more tethers 132 is fixed to (a) head 124 of firsttissue anchor 182A and (b) second tissue anchor 182B.

For some applications, such as shown in FIG. 4A, second tissue anchor182B comprises a helical tissue-coupling element 184. For example,second tissue anchor 182B may implement techniques described in PCTPublication WO 2014/108903, which is incorporated herein by reference.For other applications, such as shown in FIG. 4B, second tissue anchor182B comprises a stent 186. For example, second tissue anchor 182B mayimplement techniques described in one or more of the followingapplications, which are incorporated herein by reference: US PatentApplication Publication 2011/0184510, US Patent Application Publication2012/0035712, US Patent Application Publication 2013/0018459, US PatentApplication Publication 2013/0046380, and/or PCT Publication WO2014/141239.

Reference is made to FIGS. 1A-D and 4A-B. For some applications, shaft122 comprises a sealing element 190, which is configured to form ablood-tight seal between a portion of shaft 122 inside the heart chamberand wall 194 of the heart. For some applications, sealing element 190 isannular, and snugly surrounds shaft 122. For some applications, shaft122 further comprises a spring 192, which is disposed proximal tosealing element 190, and is configured to apply a distal force tosealing element 190, in order to push sealing element against wall 194of the heart chamber, in order to form a tight seal, such as shown inFIG. 1D.

Reference is made to FIGS. 1A-4B. For some applications, tissue anchor120 is implanted using techniques described hereinbelow with referenceto FIGS. 13A-D, 15A-C, and/or 16, optionally in combination withtechniques described in one or more of the patents and patentapplication publications incorporated hereinbelow by reference, mutatismutandis.

Reference is now made to FIGS. 5A-D, which are schematic illustrationsof a tissue anchor 200 in several stages of deployment from deploymenttool 30, in accordance with an application of the present invention.Tissue anchor 200 is one implementation of tissue anchor 20, describedabove. Other than as described below, tissue anchor 200 is generallysimilar to tissue anchor 120, described hereinabove with reference toFIGS. 1A-4B, and may implement any of the features thereof, mutatismutandis.

In this configuration, tissue-coupling element 128 typically compriseswire 150. For some applications, shaft 122 and tissue-coupling element128 are integral to one another; for example, shaft 122 andtissue-coupling element 128 may both comprise wire 150, as shown.

Deployment tool 30 is configured to constrain tissue-coupling element128 while delivering tissue-coupling element 128 through tissue.Typically, during delivery, such as shown in FIG. 5A, deployment tool 30is configured to hold tissue-coupling element 128 in an elongated,unwound configuration, which may be curvy (such as shown in FIG. 5A) orstraight (such as shown in FIG. 1A). Typically, when tissue-couplingelement 128 is constrained by the deployment tool, a longitudinalportion of flexible elongate tension member 202, described hereinbelow,runs alongside a portion of wire 150. For some applications, deploymenttool 30 comprises a removable driver 201, which comprises a driver head203 and at least one shaft 205 that is coupled to the driver head.Driver head 203 is removably coupled to anchor head 124 duringpenetration of tissue-coupling element 128 through tissue, as describedhereinbelow. The at least one shaft 205 is configured to controllablydetach the driver head from the anchor head. For example, a deploymentneedle may run through a channel of the at least one shaft; pulling onthe needle detaches the driver head from the anchor head.

When tissue anchor 200 is unconstrained by deployment tool 30, such asshown in FIGS. 5B-D, wire 150 is shaped as open loop 154 (e.g., athree-dimensional open loop), such as spiral 160 (e.g., athree-dimensional spiral) around center point 162 (labeled in FIGS. 2Band 5D). For some applications, such as shown in FIGS. 5B-D, wire 150extends from distal end 130 of shaft 122 at radially-outer end 164 ofopen loop 154 (e.g., spiral 160) (labeled in FIGS. 5C and 5D), whentissue anchor 200 is unconstrained by deployment tool 30. For someapplications, wire 150 intersects center point 162 when tissue anchor200 is unconstrained by deployment tool 30 (configuration not shown),while for other applications, wire 150 does not intersect center point162 when tissue anchor 200 is unconstrained by deployment tool 30 (asshown). For other applications, such as shown in FIGS. 8A-B, describedhereinbelow, wire 150 extends from distal end 130 of shaft 122 atradially-inner end 264 of open loop 154 (e.g., spiral 160).

For some applications, open loop 154 (e.g., spiral 160) has thedimensions described hereinabove with reference to FIGS. 2A-B and/or3A-B. For some applications, tissue-coupling element 128 has one or moreof the characteristics described hereinabove with reference to FIGS.3A-B.

Tissue anchor 200 further comprises a flexible elongate tension member202, which includes:

-   -   a distal portion 204 that is fixed to a site 206 on open loop        154 (e.g., spiral 160) (such as by welding, soldering, crimping,        and/or knotting),    -   a proximal portion 208, which has a longitudinal segment 209        that runs alongside at least a portion 210 of shaft 122 (labeled        in FIG. 5C, in which the at least a portion 210 of shaft 122 is        the entire length of shaft 122), and    -   a crossing portion 212, which (a) is disposed between distal and        proximal portions 204 and 208 along flexible elongate tension        member 202, and (ii) crosses at least a portion of open loop 154        (e.g., spiral 160) when tissue anchor 200 is unconstrained by        deployment tool 30.

Although flexible elongate tension member 202 is fixed to wire 150 oftissue-coupling element 128, flexible elongate tension member 202 istypically distinct from wire 150. In other words, flexible elongatetension member 202 and wire 150 are not two longitudinal portions of asingle continuous wire, i.e., are not longitudinally contiguous witheach other.

Tension is applied to tissue-coupling element 128 of tissue anchor 200via flexible elongate tension member 202. The applied tension isresisted by the outward force of open loop 154 (e.g., spiral 160). Theapplied tension at least partially compresses and stiffens open loop 154(e.g., spiral 160). This arrangement of tension distribution mayovercome any natural tendency of open loop 154 (e.g., spiral 160) tostraighten (i.e., unwind) if tension were to be applied along centrallongitudinal axis 134 via shaft 122, and thus may allow the applicationof a greater load to open loop 154 (e.g., spiral 160). In addition, thisstiffening technique allows open loop 154 (e.g., spiral 160) to bemanufactured less stiff than it otherwise would need to be, whichfacilitates straightening and delivering the tissue anchor, andsubsequent stiffening in situ.

Typically, before tension is applied to flexible elongate tension member202, when tissue anchor 200 is unconstrained by deployment tool 30,flexible elongate tension member 202 is not taut across the at least aportion of open loop 154 (e.g., spiral 160). For example, flexibleelongate tension member 202 may arc distally, such as can best be seenin FIG. 5C.

Typically, tissue anchor 200 is configured to allow relative axialmotion between the at least a portion 210 of shaft 122 and longitudinalsegment 209 of proximal portion 208 of flexible elongate tension member202 when tissue anchor 200 is unconstrained by deployment tool 30 (asflexible elongate tension member 202 is tensioned and pulls ontissue-coupling element 128, tissue anchor 200 becomes progressivelymore constrained by flexible elongate tension member 202; the relativeaxial motion nevertheless remains possible). In other words,longitudinal segment 209 of proximal portion 208 of flexible elongatetension member 202 is axially moveable with respect to the at least aportion 210 of shaft 122 when tissue anchor 200 is unconstrained bydeployment tool 30. Such axial motion allows tension to be applied toflexible elongate tension member 202 without also being applied to shaft122, and allows open loop 154 (e.g., spiral 160) to be unwound andflexible elongate tension member 202 to be disposed alongside a portionof flexible elongate tension member 202, as shown in FIG. 5A (in whichdeployment tool 30 constrains both constrain tissue-coupling element 128and flexible elongate tension member 202). Typically, longitudinalsegment 209 of proximal portion 208 of flexible elongate tension member202 is coupled in sliding communication with the at least a portion 210of shaft 122, when tissue anchor 200 is unconstrained by deployment tool30. For some applications, tissue anchor 200 comprises one or moreannular elements, which are disposed around the at least a portion ofshaft 122, and couple flexible elongate tension member 202 in thesliding communication with the at least a portion 210 of shaft 122, whentissue anchor 200 is unconstrained by deployment tool 30. For example,the annular elements may comprise one or more collars 244, describedhereinbelow, loops, or rings.

For some applications, flexible elongate tension member 202 is not fixedto any portion of open loop 154 (e.g., spiral 160) beyond 2 mm from site206 on open loop 154 (e.g., spiral 160), measured when tissue anchor 200is unconstrained by deployment tool 30. Alternatively or additionally,when tissue anchor 200 is unconstrained by deployment tool 30, flexibleelongate tension member 202 is not fixed to any portion of open loop 154(e.g., spiral 160) beyond a distance from site 206 on open loop 154(e.g., spiral 160), which distance equals 30% of greatest lateraldimension D3 of open loop 154 (e.g., spiral 160) of tissue-couplingelement 128, measured perpendicular to central longitudinal axis 134(labeled in FIG. 2A). For some applications, flexible elongate tensionmember 202 is fixed to open loop 154 (e.g., spiral 160) only at site 206on open loop 154 (e.g., spiral 160). Alternatively, a distal portion offlexible elongate tension member 202 beyond site 206 is fixed to openloop 154 (e.g., spiral 160), such as described hereinbelow withreference to FIGS. 9E and 9F.

Typically, when tissue anchor 200 is unconstrained by deployment tool30, the at least a portion of open loop 154 (e.g., spiral 160) crossedby crossing portion 212 has a length that equals at least 33% ofgreatest lateral dimension D3 of open loop 154 (e.g., spiral 160) oftissue-coupling element 128, measured perpendicular to centrallongitudinal axis 134 (labeled in FIG. 2A), e.g., at least 50% ofgreatest lateral dimension D3, such as at least 75% of greatest lateraldimension D3, e.g., at least 90% of greatest lateral dimension D3.

For some applications, as shown, site 206 is on an outermost turn 214 ofopen loop 154 (e.g., spiral 160) (labeled in FIG. 5D), when tissueanchor 200 is unconstrained by deployment tool 30. For some otherapplications, site 206 is on a second-to-outermost turn 216 of open loop154 (e.g., spiral 160) (labeled in FIG. 5D), when tissue anchor 200 isunconstrained by deployment tool 30 (configuration not shown).

Typically, a radius of flexible elongate tension member 202 is less thana radius of wire 150, such as less than 50% of the radius of wire 150.As mentioned above with reference to FIGS. 1B-C and 2A-C, for someapplications a cross-sectional area of wire 150 is at least 0.09 mm2(such as at least 0.18 mm2), no more than 3 mm2 (e.g., no more than 2.9mm2), and/or between 0.09 mm2 (such as 0.18 mm2) and 3 mm2 (e.g., 2.9mm2). For some applications, flexible elongate tension member 202comprises metal, such as a metal alloy, e.g., Nitinol. For someapplications, flexible elongate tension member 202 comprises radiopaquesections or is radiopaque, to enable observation of the relativemovement when tensioning.

For some applications, site 206 on open loop 154 (e.g., spiral 160) is afirst site 206 on open loop 154 (e.g., spiral 160), and, when tissueanchor 200 is unconstrained by deployment tool 30 and flexible elongatetension member 202 is tensioned straight, (a) wire 150 extends fromdistal end 130 of shaft 122 at a second site 218 on open loop 154 (e.g.,spiral 160), and (b) if tissue-coupling element 128 and flexibleelongate tension member 202 were to be projected onto plane 136 that isperpendicular to central longitudinal axis 134, an angle ⊖ (theta)between the first and the second sites, having a vertex 242 at centerpoint 162, would be between 130 and 180 degrees, such as between 150 and180 degrees, e.g., between 170 and 180 degrees (labeled in FIG. 5D). Forsome applications, as shown, second site 218 is at radially-outer end164 of open loop 154 (e.g., spiral 160).

Alternatively or additionally, for some applications, as labeled in FIG.5D, when tissue anchor 200 is unconstrained by deployment tool 30 andflexible elongate tension member 202 is tensioned straight, iftissue-coupling element 128 and flexible elongate tension member 202were to be projected onto plane 136 that is perpendicular to centrallongitudinal axis 134, an angle φ (phi) between (a) flexible elongatetension member 202 and (b) a tangent 250 to open loop 154 (e.g., spiral160) at site 206 would be between 45 and 90 degrees, such as between 70and 90 degrees, e.g., 90 degrees.

As mentioned above with reference to FIGS. 1A-D and 4A-B, for someapplication shaft 122 comprises sealing element 190. For someapplications, sealing element 190 one or more collars 244 disposedaround shaft 122, and, typically, a sleeve 246 that couples the collars244 together. Sleeve 246 defines a lumen having proximal and distalends. The flexible elongate tension member 202 slidingly passes throughthe lumen and its ends. (Sleeve 246 is shown in FIGS. 5A and 6A-B; forclarity of illustration, sleeve 246 is shown as transparent in FIG. 5B,and is not shown in FIG. 5C.) In this configuration, sealing element 190is typically sized and shaped to be inserted into the incision throughthe heart wall, and to provide a blood-tight seal. Sleeve 246, ifprovided, occludes blood flow to provide the seal. For someapplications, sleeve 246 promotes hemostasis. Optionally, filament orfiber is provided within sleeve 246 to promote hemostasis. For someapplications, collars 244 comprise a distal guide collar 244A and aproximal driver collar 244B, which optionally is a component of orserves as head 124. For some applications, a proximal end of shaft 122is disposed within proximal driver collar 244B, as shown. For someapplications, one or more of collars 244 are radiopaque or comprise aradiopaque marker. For example, sleeve 246 may comprise Dacron, and/ormay be coated and/or woven to facilitate clotting.

For other applications, sealing element 190 has the configurationdescribed hereinabove with reference to FIGS. 1A-D and 4A-B, or theconfiguration described hereinbelow with reference to FIGS. 9A-F or FIG.9G.

For some applications, a proximally-facing surface defined bytissue-coupling element 128 is convex when tissue anchor 200 isunconstrained by deployment tool 30, such as shown in FIGS. 2C and 5B-C.For other applications, a proximally-facing surface defined bytissue-coupling element 128 is concave when tissue anchor 200 isunconstrained by deployment tool 30, such as shown in FIG. 2B.

For some applications, one or more tethers 132 are provided, which areconfigured to be coupled to tissue anchor 200. Typically, the one ormore tethers 132 are fixed to flexible elongate tension member 202,typically to proximal portion 208 of the tension member, such as at ornear (e.g., within 1 cm of) a proximal end of proximal portion 208. Thisis unlike the configuration described hereinabove with reference toFIGS. 1A-D, in which head 124 of tissue anchor 120 is coupled to the oneor more tethers. In the present configuration, when tension is appliedto the one or more tethers, the tension is transmitted to flexibleelongate tension member 202, rather than to shaft 122 via head 124. Inthese applications, the one or more tethers are (a) fixed to the secondtissue anchor and (b) not fixed to shaft 122 of first tissue anchor 200.

For some applications, a radially-inner end 264 of open loop 154 (e.g.,spiral 160) is bent proximally, such as can be best seen in FIG. 5C.Because of the bend, radially-inner end 264 may help tissue-couplingelement 128 resist rotation and uncoiling.

Reference is now made to FIGS. 6A-B, which are schematic illustrationsof two configurations of a tissue anchor system 248, in accordance withrespective applications of the present invention. In these applications,tissue anchor 200 is a first tissue anchor 182A of tissue anchor system248, which further comprises (a) a second tissue anchor 182B, which isseparate and distinct first tissue anchor 182A, and (b) the one or moretethers 132, which are configured to couple (i) flexible elongatetension member 202 of first tissue anchor 182A to (ii) second tissueanchor 182B. For some applications, one of the one or more tethers 132is fixed to (a) flexible elongate tension member 202 of first tissueanchor 182A to (b) second tissue anchor 182B.

For some applications, such as shown in FIG. 6A, second tissue anchor182B comprises helical tissue-coupling element 184. For example, secondtissue anchor 182B may implement techniques described in PCT PublicationWO 2014/108903, which is incorporated herein by reference. For otherapplications, such as shown in FIG. 6B, second tissue anchor 182Bcomprises stent 186. For example, second tissue anchor 182B mayimplement techniques described in one or more of the followingapplications, which are incorporated herein by reference: US PatentApplication Publication 2011/0184510, US Patent Application Publication2012/0035712, US Patent Application Publication 2013/0018459, US PatentApplication Publication 2013/0046380, PCT Publication WO 2014/141239,and/or the patents and patent application publications incorporatedhereinbelow by reference.

Reference is now made to FIGS. 7A-B, which are schematic illustrationsof open loop 154 (e.g., spiral 160) of tissue anchor 200 unconstrainedby deployment tool 30 and under tension, respectively, in accordancewith an application of the present invention. In the state shown in FIG.7A, tissue anchor 200 (and open loop 154 (e.g., spiral 160) thereof) isunconstrained by deployment tool 30. In this state, open loop 154 (e.g.,spiral 160) has a first outer dimension D5, measured in a directionparallel to flexible elongate tension member 202. After tension isapplied to flexible elongate tension member 202, flexible elongatetension member 202 becomes more narrow in the direction of flexibleelongate tension member 202, such that open loop 154 (e.g., spiral 160)has a second outer dimension D6, measured in a direction parallel toflexible elongate tension member 202, which is less than first outerdimension D5, e.g., no more than 90% of D5, such as no more than 80% ofD5, e.g., no more than 70% of D5, no more than 50% of D5, or no morethan 20% of D5.

For some applications, the force applied to flexible elongate tensionmember 202 to achieve this reduction is between 2 and 50 N, such asbetween 5 and 20 N, e.g., 5 N, 7 N, 10 N, 20 N, or 30 N. The amount offorce is dependent on the radius of wire 150, and may increase as apower of the radius, such as a third or fourth power of the radius. Forsome applications, a smallest radius of wire 150 is chosen that is ableto withstand between 5 and 20 N of force.

Reference is now made to FIGS. 8A and 8B, which are schematicillustrations of two configurations of a tissue anchor 258, inaccordance with respective applications of the present invention. Tissueanchor 258 is one implementation of tissue anchor 20, described above.Other than as described below, tissue anchor 258 is generally similar totissue anchor 200, described hereinabove with reference to FIGS. 5A-7B,and may implement any of the features thereof, mutatis mutandis. Inaddition, tissue anchor 258 may implement any of the features of tissueanchor 120, described hereinabove with reference to FIGS. 1A-4B, mutatismutandis.

Tissue-coupling element 128 of tissue anchor 258 comprises wire 150,which is shaped as an open loop 256, e.g., a spiral 260. Wire 150extends from distal end 130 of shaft 122 at a radially-inner end 264 ofopen loop 256 (e.g., spiral 260), when tissue anchor 220 isunconstrained by deployment tool 30. This is unlike the typicalconfigurations of open loop 154 (e.g., spiral 160), describedhereinabove, in which wire 150 extends from distal end 130 of shaft 122at radially-outer end 164 of open loop 154 (e.g., spiral 160). In thepresent configurations, when tissue anchor 220 is unconstrained bydeployment tool 30, radially-inner end 264 of open loop 256 (e.g.,spiral 260) is typically disposed within 15 mm of center point 162, suchas coinciding with center point 162.

In the configuration shown in FIG. 8A, tissue anchor 258 comprisesexactly one flexible elongate tension member 202, which includes:

-   -   distal portion 204 that is fixed to site 206 on open loop 256        (e.g., spiral 260),    -   longitudinal segment 209 of proximal portion 208 that runs        alongside the at least a portion 210 of shaft 122 (labeled in        FIG. 5C), and    -   crossing portion 212, which (a) is disposed between distal and        proximal portions 204 and 208 along flexible elongate tension        member 202, and (ii) crosses at least a portion of open loop 256        (e.g., spiral 260) when tissue anchor 258 is unconstrained by        deployment tool 30.

For some applications, as shown, site 206 is on outermost turn 214 ofopen loop 256 (e.g., spiral 260), when tissue anchor 258 isunconstrained by deployment tool 30. Flexible elongate tension member202 may implement any of the features described hereinabove withreference to FIGS. 5A-7B, mutatis mutandis.

In the configuration shown in FIG. 8B, tissue anchor 258 comprises twoflexible elongate tension members 202A and 202B, which include:

-   -   respective distal portions 204A and 204B that are fixed to        respective sites 206A and 206B on open loop 256 (e.g., spiral        260),    -   respective proximal portions 208, which have respective        longitudinal segments that run alongside the at least a portion        210 of shaft 122 (labeled in FIG. 5C); these proximal portions        may join one another at some point along the proximal portions        (such as within or proximal to proximal driver collar 244B), or        may otherwise be coupled to one another along respective portion        of the proximal portions, and    -   respective crossing portions 212A and 212B, which (a) are        disposed between respective distal and proximal portions 204A        and 208B along flexible elongate tension members 202A and 202B,        respectively, and (ii) cross at least respective portions of        open loop 256 (e.g., spiral 260) when tissue anchor 258 is        unconstrained by deployment tool 30.

For some applications, as shown, sites 206A and 206B are on outermostturn 214 of open loop 256 (e.g., spiral 260), when tissue anchor 258 isunconstrained by deployment tool 30. Flexible elongate tension members202A and 202B may implement any of the features described hereinabovewith reference to FIGS. 5A-7B, mutatis mutandis.

Reference is now made to FIGS. 9A-D, which are schematic illustrationsof a tissue anchor 300, in accordance with an application of the presentinvention. Tissue anchor 300 is one implementation of tissue anchor 20,described above. Other than as described below, tissue anchor 300 isgenerally similar to tissue anchor 200, described hereinabove withreference to FIGS. 5A-D, and may implement any of the features thereof,mutatis mutandis. For some applications, tissue anchor 300 isimplemented using the configuration of FIGS. 6A or 6B, mutatis mutandis.

When tissue anchor 300 is unconstrained by deployment tool 30, such asshown in FIGS. 9A-C, wire 150 is shaped as open loop 154 (e.g., athree-dimensional open loop) around center point 162 (labeled in FIGS.2B and 5D), and, optionally, as spiral 160 (e.g., a three-dimensionalspiral) around center point 162 (labeled in FIGS. 2B and 5D). For someapplications, such as shown in FIGS. 9A-C, wire 150 extends from distalend 130 of shaft 122 at radially-outer end 164 of open loop 154 (and,optionally, spiral 160) (labeled in FIG. 9A), when tissue anchor 300 isunconstrained by deployment tool 30. For some applications, open loop154 (and, optionally, spiral 160) has the dimensions describedhereinabove with reference to FIGS. 2A-B and/or 3A-B. For someapplications, tissue-coupling element 128 has one or more of thecharacteristics described hereinabove with reference to FIGS. 3A-B. Forsome applications, the proximally-facing surface defined bytissue-coupling element 128 is generally flat, when tissue anchor 300 isunconstrained by deployment tool 30 (configuration not shown).Optionally, upon coming into full contact with the external surface ofthe heart, the proximally-facing surface defined by the tissue-couplingelement may assume a concave shape conforming to the convex shape of theexternal surface of the heart.

In the configuration shown in FIGS. 9A-D, tissue anchor 300 furthercomprises a flexible elongate tension member 202, which includes:

-   -   distal portion 204 that is fixed to site 206 on open loop 154        (such as by welding, soldering, crimping, and/or knotting,        and/or as described hereinbelow with reference to FIG. 9E and/or        FIG. 9F),    -   proximal portion 208, which has longitudinal segment 209 that        runs alongside at least portion 210 of shaft 122 (labeled in        FIG. 9B, in which the at least a portion 210 of shaft 122 is the        entire length of shaft 122), and    -   crossing portion 212, which (a) is disposed between distal and        proximal portions 204 and 208 along flexible elongate tension        member 202, and (ii) crosses at least a portion of open loop 154        when tissue anchor 300 is unconstrained by deployment tool 30.

Although flexible elongate tension member 202 is fixed to wire 150 oftissue-coupling element 128, flexible elongate tension member 202 istypically distinct from wire 150. In other words, flexible elongatetension member 202 and wire 150 are not two longitudinal portions of asingle continuous wire, i.e., are not longitudinally contiguous witheach other.

Tension is applied to tissue-coupling element 128 of tissue anchor 300via flexible elongate tension member 202. The applied tension isresisted by the outward force of open loop 154. The applied tension atleast partially compresses and stiffens open loop 154. This arrangementof tension distribution may overcome any natural tendency of open loop154 to straighten (i.e., unwind) if tension were to be applied alongcentral longitudinal axis 134 via shaft 122, and thus may allow theapplication of a greater load to open loop 154.

Typically, before tension is applied to flexible elongate tension member202, when tissue anchor 300 is unconstrained by deployment tool 30,flexible elongate tension member 202 is not taut across the at least aportion of open loop 154. For example, flexible elongate tension member202 may arc distally, such as can best be seen in FIG. 9A.

Typically, tissue anchor 300 is configured to allow relative axialmotion between the at least a portion 210 of shaft 122 and longitudinalsegment 209 of proximal portion 208 of flexible elongate tension member202 when tissue anchor 300 is unconstrained by deployment tool 30. Suchaxial motion allows tension to be applied to flexible elongate tensionmember 202 without also being applied to shaft 122, and allows open loop154 to be unwound and flexible elongate tension member 202 to bedisposed alongside a portion of flexible elongate tension member 202, asshown in FIG. 9A. Typically, longitudinal segment 209 of proximalportion 208 of flexible elongate tension member 202 is coupled insliding communication with the at least a portion 210 of shaft 122, whentissue anchor 300 is unconstrained by deployment tool 30. For someapplications, tissue anchor 300 comprises one or more annular elements,which are disposed around the at least a portion of shaft 122, andcouple flexible elongate tension member 202 in the sliding communicationwith the at least a portion 210 of shaft 122, when tissue anchor 300 isunconstrained by deployment tool 30. For example, the annular elementsmay comprise one or more collars, loops, or rings. Shaft 122 (e.g., thecollars) is shaped such that flexible elongate tension member 202 runsgenerally parallel to central longitudinal axis 134 of shaft 122.

For some applications, as shown, site 206 is on an outermost turn ofopen loop 154, when tissue anchor 300 is unconstrained by deploymenttool 30. For some other applications, site 206 is on asecond-to-outermost turn of open loop 154, when tissue anchor 300 isunconstrained by deployment tool 30 (configuration not shown).

Typically, a radius of flexible elongate tension member 202 is less thana radius of wire 150, such as less than 50% of the radius of wire 150.Flexible elongate tension member 202 and/or wire 150 may have any of thecharacteristics described hereinabove with reference to FIGS. 2A-C,3A-B, and/or 5A-D, including dimensions and relative arrangement withrespect to each other.

For some applications, one or more tethers 132 are provided, which areconfigured to be coupled to tissue anchor 300. Typically, the one ormore tethers 132 are fixed to flexible elongate tension member 202,typically to proximal portion 208 of the tension member, such as at ornear (e.g., within 1 cm of) a proximal end of proximal portion 208. Whentension is applied to the one or more tethers, the tension istransmitted to flexible elongate tension member 202, rather than toshaft 122 via head 124.

For some applications, head 124 is shaped so as to define a passage 272in which proximal portion 208 of flexible elongate tension member 202 isslidably disposed. Flexible elongate tension member 202 comprises alocking stopper 270, which is axially fixed to proximal portion 208 orcrossing portion 212 of flexible elongate tension member 202. Lockingstopper 270 and passage 272 are sized and shaped such that the size andshape of passage 272 prevent proximal movement of locking stopper 270past passage 272. Optionally, locking stopper 270 engages passage 272(as shown). For some applications, passage 272 is a channel through aportion of head 124 (such as through one or more collars of head 124)(as shown), while for other applications, passage 272 is a groove (e.g.,a U-shaped groove) (configuration not shown). For some applications,locking stopper 270 is shaped so as to define a base 274 and a flange276. The flange is too large to pass through passage 272, while base 274may or may not be too large to enter the passage. For some applications,locking stopper 270 is manufactured as a separate element that is fixedto flexible elongate tension member 202, such as by crimping, welding,or soldering. For other applications, locking stopper 270 is integral toflexible elongate tension member 202.

For some applications, passage 272 extends to a distal end of head 124(as shown), while for other applications, passage 272 is disposed moreproximally in head 124, such as near a proximal end of head 124(configuration not shown). Typically, locking stopper 270 is axiallyfixed to proximal portion 208 or crossing portion 212 of flexibleelongate tension member 202 at a distance of at least 7 mm, no more than22 mm, and/or between 7 and 22 mm from site 206 on the open loop,measured along flexible elongate tension member 202 (i.e., measuredalong the curvature of flexible elongate tension member 202 if it iscurved, such as shown in FIGS. 9A-B). Alternatively or additionally, forsome applications, if tissue-coupling element 128 were straightened inan elongated configuration, for example by being disposed in deploymenttool 30 such as shown in FIG. 1A mutatis mutandis, locking stopper 270would be a distance of at least 7 mm, no more than 12 mm, and/or between7 and 12 mm (e.g., 10 mm) from passage 272. Alternatively oradditionally, for some applications, when tissue anchor 300 isunconstrained by deployment tool 30 (and flexible elongate tensionmember 202 is curved, such as shown in FIGS. 9A-B), locking stopper 270is disposed at a distance of at least 7 mm, no more than 12 mm, and/orbetween 7 and 12 mm (e.g., 10 mm) from passage 272. For someapplications, when sufficient tension is applied to flexible elongatetension member 202 straighten flexible elongate tension member 202 butnot compress open loop 154, locking stopper 270 moves between 5 and 8 mmtoward passage 272, such that locking stopper 270 is disposed at adistance of at least 2 mm, no more than 5 mm, and/or between 2 and 5 mm(e.g., 10 mm) from passage 272.

As shown in FIG. 9C-D, tension is applied to tissue-coupling element 128of tissue anchor 200 via flexible elongate tension member 202. Theapplied tension is resisted by the outward force of open loop 154. Theapplied tension at least partially compresses and stiffens open loop154. This arrangement of tension distribution may overcome any naturaltendency of open loop 154 to straighten (i.e., unwind) if tension wereto be applied along central longitudinal axis 134 via shaft 122, andthus may allow the application of a greater load to open loop 154. Thetension applied to tissue-coupling element 128 thus locks open loop 154into a desired shape.

Locking stopper 270 limits the total load that can be applied to openloop 154 by flexible elongate tension member 202, thereby reducingexcessive, unnecessary strain on open loop 154. For example, the first1.5 to 5 N of force applied to flexible elongate tension member 202 maysufficiently deform open loop 154 and engage locking stopper 270.Additional load (tension) that is applied by flexible elongate tensionmember 202 pulls on the entire anchor 300, and does not further increasethe load applied across open loop 154 to site 206, and thus does notfurther compress the open loop. As described hereinbelow with referenceto FIGS. 14D and 15A-C, such tension may be applied to pull anchor 300closer to another tissue anchor, in order to facilitate repair of anatrioventricular valve of the subject, such as tricuspid valve 504.

These techniques thus allow the use of relatively flexibletissue-coupling element, in order to not generate too much outward forceinside a delivery tube, which might make axial movement of thetissue-coupling element in the delivery tube difficult or impossible.The tissue-coupling element is tensioned upon delivery, thereby changingits shape and providing a strong tissue-coupling element that cannotunwind easily, and thus remains coupled to the tissue. In addition,minimizing the load on attachment site 206 provides a mechanicaladvantage that increases the durability of the device under higherloads.

As mentioned above, open loop 154 may have more than one turn and lessthan 1.5 turns, such as more than one turn, e.g., more than 1.01 turns(363.6 degrees), such as more than 1.02 turns (367.2 degrees), and/orless than 1.25 turns (450 degrees) (one turn equals 360 degrees).Providing open loop 154 with more than one turn, rather than exactly oneturn or less than one turn, prevents crossing portion 212 from slidingdown off of open loop 154 and onto shaft 122 when tension is applied tocrossing portion 212. Such sliding might result in crossing portion 212cutting into tissue of the heart.

Reference is made to FIGS. 9E and 9F, which are schematic illustrationsof alternative ways to fix flexible elongate tension member 202 to site206 of open loop 154, in accordance with respective applications of thepresent invention. These techniques may be used for tissue anchor 200 ortissue anchor 300. In the configuration shown in FIG. 9E, distal portion204 of flexible elongate tension member 202 is fixed to site 206 on openloop 154 by crimping a crimping element 288 around wire 150. In thisconfiguration, a distal portion of flexible elongate tension member 202beyond site 206 is fixed (e.g., by welding or soldering) to open loop154, such as near radially-inner end 264 of open loop 154. The portionof flexible elongate tension member 202 between site 206 andradially-inner end 264 may be attached to wire 150, or may be held nearwire 150, such as by a sleeve, as described with reference to FIG. 9F.It is noted that site 206 is the site on open loop 154 at which flexibleelongate tension member 202 makes functional contact with the loop forapplying tension across the loop, rather than other sites along wire 150to which flexible elongate tension member 202 may also be attached.

The configuration shown in FIG. 9F may be used in combination with theconfiguration shown in FIG. 9E, or separately. In the configurationshown in FIG. 9F, open loop 154 is covered with a sleeve 280, which maycomprise a woven material, comprising, for example, polyester. A distalportion of flexible elongate tension member 202 beyond site 206 is fixed(e.g., by welding or soldering) to open loop 154, such as nearradially-inner end 264 of open loop 154 (this area of open loop 154 mayfacilitate attachment because this area is straighter than otherportions of the open loop). Flexible elongate tension member 202penetrates and exits sleeve 280 at site 206, such as by passing betweenthe fibers of sleeve 280, or through an opening made in sleeve 280,which opening is optionally reinforced. Distal portion 204 of flexibleelongate tension member 202 is fixed to site 206 on open loop 154indirectly by being restrained by sleeve 280. Sleeve 280 may in additionimprove tissue growth on the anchor. Optionally, a more proximal portionof flexible elongate tension member 202, after crossing open loop 154,re-enters sleeve 280 through a lateral wall of the sleeve, and exits theproximal end of the sleeve.

Reference is made to FIG. 9G, which is a schematic illustration ofanchor 300 comprising a sealing element 318, in accordance with anapplication of the present invention. Sealing element 318 is similar insome respects to sealing element 190, described hereinabove withreference to FIGS. 1A-D and 4A-B. Sealing element 318 is configured toform a blood-tight seal between a portion of head 124 inside the heartchamber and wall 194 of the heart. For some applications, sealingelement 318 comprises a compressible sponge. For some applications, anouter diameter of sealing element 318, when expanded, equals at least1.5 times, e.g., at least 2 times, an inner diameter of shaft 34 ofdeployment tool 30, described hereinabove with reference to FIG. 1A. Forsome applications, sealing element 318 is disposed on the narrowerportion of head 124 between two collars, which can be seen in FIGS.9A-F.

Reference is now made to FIG. 9H, which is a schematic illustration of atissue anchor 290, in accordance with an application of the presentinvention. Except as described below, anchor 290 is generally similar toanchor 300, described hereinabove with reference to FIGS. 9A-G. Wire 150of anchor 290 is not shaped as open loop 154. Instead, wire 150 isshaped as an open shape 291, such as a portion of a circle or a portionof an ellipse. Typically, if tissue-coupling element 128 were to beprojected onto plane 136 that is perpendicular to central longitudinalaxis 134 of shaft 122, open shape 291 would surround at least 170degrees, no more than 355 degrees, and/or between 170 and 355 degrees ofa point 292 in plane 136, such as at least 180 degrees (e.g., at least190 degrees), no more than 345 degrees, and/or between 180 degrees(e.g., 190 degrees) and 345 degrees. For some applications, such as inwhich open shape 291 surrounds between 170 and 190 degrees of point 292,site 206 is at a distal end 294 of wire 150. For some of theseapplications, wire 150 is shaped so as to define a channel, throughwhich a portion of flexible elongate tension member 202 passes and exitswire 150 at distal end 294 of wire 150.

Reference is now made to FIG. 9I, which is a schematic illustration ofanother configuration of open loop 154, in accordance with anapplication of the present invention. This configuration may be used incombination tissue anchors 120, 200, 258, 290, and 300. In thisconfiguration, when the tissue anchor is unconstrained by deploymenttool 30, open loop 154 is shaped so as to define one or more curvedportions 296 (e.g., two or more curved portions 296) and one or morestraight portions 298 (e.g., two or more straight portions 298).Straight portions 298 generally maximize the surface contact with theexternal surface of the heart and thus provide good anchoring. For someapplications, open loop 154 is shaped as a common, conventional paperclip (an oblong shape with straight sides, with approximately 1.5turns).

Reference is now made to FIGS. 10A-B, which are schematic illustrationsof a tissue anchor 220 in several stages of deployment from deploymenttool 30, in accordance with an application of the present invention.Tissue anchor 220 is one implementation of tissue anchor 20, describedabove. Tissue anchor 120 typically comprises (a) a shaft 222, and (b) atissue-coupling element 228, which extends from a distal end 230 ofshaft 222, and which comprises three or more tines 232, such as four ormore tines 232.

FIG. 10A shows tissue-coupling element 228 fully constrained bydeployment tool 30. When tissue anchor 220 is fully constrained bydeployment tool 30, tissue-coupling element 228 typically has an outerdiameter of at least 1 mm, no more than 4 mm, and/or between 1 and 4 mm.

FIG. 10B shows tissue-coupling element 228 released from deployment tool30, while a portion of tissue anchor 220 is still constrained bydeployment tool 30. Deployment tool 30 may have any of the featuresdescribed hereinabove with reference to FIGS. 1A-D.

When tissue anchor 220 is unconstrained by deployment tool 30:

-   -   shaft 222 has a central longitudinal axis 234,    -   tines 232 extend radially outward from central longitudinal axis        234 in respective directions that are fixed with respect to one        another, and    -   tissue-coupling element 228 is shaped such that if        tissue-coupling element 228 were to be projected onto a plane        236 that is perpendicular to central longitudinal axis 234, at        least 80% (e.g., at least 90%, such at least 95%) of an area 238        of a projection 239 of tissue-coupling element 228 on plane 236        would fall within an angle c (epsilon) of 210 degrees in plane        236 having a vertex 240 at central longitudinal axis 234.

For some applications, at least one pair of circumferentially-adjacentones of tines 232 (e.g., all pairs) is offset by an angle of at least 30degrees, no more than 60 degrees, and/or between 30 and 60 degrees. Forsome applications, the respective angles betweencircumferentially-adjacent ones of tines 232 vary by less than 10%,e.g., are equal to one another.

For some applications, tissue anchor 220 further comprises a headconnected to a proximal portion of shaft 222 (configuration not shown);for example, the head may be head 124, described hereinabove withreference to FIGS. 1A-D. For some applications, the one or more tethers132, described hereinabove with reference to FIGS. 1A-D, are provided;one of the one or more tethers 132 is configured to be coupled to tissueanchor 220, such as to the head of tissue anchor 220; for example, oneof the one or more tethers 132 may be fixed to the head.

For some applications, tissue anchor 220 is a first tissue anchor of atissue anchor system, which further comprises (a) a second tissueanchor, which is separate and distinct from the first tissue anchor, and(b) the one or more tethers 132, which are configured to couple (a) thefirst tissue anchor to (b) the second tissue anchor. The one or moretethers and second tissue anchor may implement any of the techniquesdescribed hereinabove with reference to FIGS. 4A-B, mutatis mutandis.

For some applications, central longitudinal axis 234 is straight whentissue-coupling element 228 is unconstrained by deployment tool 30, suchas shown in FIG. 10B. For some applications, shaft 222 is flexible. Forsome applications, distal ends 252 of tines 232 do not define respectivesharp distal tips; for example, the distal ends may be blunt.Tissue-coupling element 228 is non-helical when tissue anchor 220 isunconstrained by deployment tool 30.

For some applications, a proximally-facing surface defined bytissue-coupling element 228 is concave when tissue anchor 220 isunconstrained by deployment tool 30.

For some applications (labeled in FIG. 10B), when tissue anchor 220 isunconstrained by deployment tool 30:

-   -   greatest longitudinal dimension D2 of tissue-coupling element        228, measured parallel to central longitudinal axis 234, is        between 0 and 6 mm (such as between 1 and 5 mm), and    -   greatest lateral dimension D3 of tissue-coupling element 228,        measured perpendicular to central longitudinal axis 234, is        between 4 and 25 mm (such as between 5 and 24 mm).

For some applications, angle c (epsilon) is a first angle c (epsilon).At least 80% (e.g., at least 90%, such as at least 95%) of area 238 ofprojection 239 of tissue-coupling element 228 on plane 236 would fallwithin a second angle (zeta) of 180 degrees in plane 236 having vertex240 at central longitudinal axis 234.

Reference is again made to FIGS. 10A-B. For some applications, tissueanchor 220 is implanted using techniques described hereinbelow withreference to FIGS. 13A-D, 15A-C, and/or 16, mutatis mutandis.

Reference is now made to FIGS. 11A-C, which are schematic illustrationsof several views of a tissue anchor 320, in accordance with anapplication of the present invention. Tissue anchor 320 is oneimplementation of tissue anchor 20, described above. Except as describedbelow, tissue anchor 320 is similar to tissue anchor 220, describedhereinabove with reference to FIGS. 10A-B, and may incorporate any ofthe features thereof. A tissue-coupling element 328 of tissue anchor 320further comprises one or more membranes 342 that are fixed to and extendbetween circumferentially-adjacent ones of tines 232. The membranes andtines together might be considered to define a structure similar in somerespect to a bat wing, or a partial umbrella. The membranes may helpevenly distribute the force on the external surface of the heart appliedby the tissue-coupling element, and/or may provide a seal to the heartwall. For some applications, membranes 342 comprise a polymer orpolymeric (synthetic or natural) mesh to promote tissue integration.

Reference is still made to FIGS. 11A-C. For some applications, tissueanchor 320 is implanted using techniques described hereinbelow withreference to FIGS. 13A-D, 15A-C, and/or 16, mutatis mutandis.

Reference is now made to FIGS. 12A-C, which are schematic illustrationsof a tissue anchor 420, in accordance with an application of the presentinvention. Tissue anchor 420 is one implementation of tissue anchor 20,described above. Except as described below, tissue anchor 420 is similarto tissue anchor 320, described hereinabove with reference to FIGS.11A-C, and may incorporate any of the features thereof. Atissue-coupling element 428 of tissue anchor 420 comprises:

-   -   three or more first tines 432A, such as four or more first tines        432A, which are typically rotationally fixed with respect to one        another;    -   three or more second tines 432B, such as four or more second        tines 432B, which are typically rotationally fixed with respect        to one another;    -   one or more first membranes 442A that are fixed to and extend        between circumferentially-adjacent ones of first tines 432A, and        are not fixed to any of second tines 432B; and    -   one or more second membranes 442B that are fixed to and extend        between circumferentially-adjacent ones of second tines 432B,        and are not fixed to any of first tines 432A.

The first membranes and first tines together might be considered todefine a structure similar in some respect to a first bat wing 444A, ora first partial umbrella 444A, and the second membranes and second tinestogether might be considered to define a structure similar in somerespect to a second bat wing 444B, or a second partial umbrella 444B.

For some applications, tissue anchor 420 is configured such that secondtines 432B are rotatable with respect to first tines 432A. As a result,the first bat wing (or partial umbrella) 444A is rotatable with respectto the second bat wing (or partial umbrella) 444B. Such rotation allowsadjustment of the total collective coverage of the first and secondmembranes (and bat wings), in order to adjust the total angular coverageof tissue-coupling element 428. First tines 432A are disposed atdifferent axial heights from second tines 432B, in order to allow one ofthe bat wings (or partial umbrellas) to rotate over the other.

For some applications, first tines 432A are rotationally fixed withrespect to shaft 222 (although the shaft itself maybe rotatable). Forsome applications, tissue anchor 420 comprises a second shaft, andsecond tines 432B are rotationally fixed with respect the second shaft.The second shaft is rotatable with respect to shaft 222. Typically, thesecond shaft is disposed within a lumen of shaft 222, or shaft 222 isdisposed within a lumen of the second shaft.

For some applications, when tissue anchor 420 is unconstrained bydeployment tool 30, tissue-coupling element 428 is shaped such that:

-   -   (a) first membranes 442A extend circumferentially around central        longitudinal axis 234 between 90 and 180 degrees, and (b) second        membranes 442B extend circumferentially around central        longitudinal axis 234 between 90 and 180 degrees; and/or    -   (a) first membranes 442A extend circumferentially around central        longitudinal axis 234 a first number of degrees, (b) second        membranes 442B extend circumferentially around central        longitudinal axis 234 a second number of degrees, and (c) a sum        of the first and second numbers of degrees is between 100 and        350 degrees, such as between 150 and 270 degrees.

For some applications, a proximally-facing surface defined bytissue-coupling element 428 is concave when tissue anchor 420 isunconstrained by deployment tool 30.

For some applications, tissue anchor 420 does not comprise membranes442A or 442B (configuration not shown). Thus, in these applications,tissue-coupling element 428 of tissue anchor 420 comprises:

-   -   three or more first tines 432A, such as four or more first tines        432A, which are rotationally fixed with respect to one another;        and    -   three or more second tines 432B, such as four or more second        tines 432B, which are rotationally fixed with respect to one        another.

In these applications, tissue anchor 420 is configured such that secondtines 432B are rotatable with respect to first tines 432A. Such rotationallows adjustment of the total collective coverage of first tines 432Aand second tines 432B, in order to adjust the total angular coverage oftissue-coupling element 428. First tines 432A are disposed at differentaxial heights from second tines 432B, in order to allow one set of thetines to rotate over the other.

For some of these applications, first tines 432A are rotationally fixedwith respect to shaft 222 (although the shaft itself maybe rotatable).For some applications, tissue anchor 420 comprises a second shaft, andsecond tines 432B are rotationally fixed with respect the second shaft.The second shaft is rotatable with respect to shaft 222. Typically, thesecond shaft is disposed within a lumen of shaft 222, or shaft 222 isdisposed within a lumen of the second shaft.

For some of these applications, when tissue anchor 420 is unconstrainedby deployment tool 30, tissue-coupling element 428 is shaped such that:

-   -   (a) first tines 432A extend circumferentially around central        longitudinal axis 234 between 90 and 180 degrees, and (b) second        tines 432B extend circumferentially around central longitudinal        axis 234 between 90 and 180 degrees; and/or    -   (a) first tines 432A extend circumferentially around central        longitudinal axis 234 a first number of degrees, (b) second        tines 432B extend circumferentially around central longitudinal        axis 234 a second number of degrees, and (c) a sum of the first        and second numbers of degrees is between 100 and 350 degrees,        such as between 150 and 270 degrees.

Reference is made to FIGS. 12A-C. For some applications, tissue anchor420 is implanted using techniques described hereinbelow with referenceto FIGS. 13A-D, 15A-C, and/or 16, mutatis mutandis to provide for therotation of second tines 432B with respect to first tines 432A.Typically, first tines 432A are rotated with respect to the externalsurface of the heart to avoid overlying coronary blood vessels, such asa right coronary artery (RCA) 590, and second tines 432B are rotatedwith respect to first tines 432A to adjust the total angular coverage oftissue-coupling element 428 to avoid overlying coronary blood vessels.

Reference is now made to FIGS. 13A-D, which are schematic illustrationsof a method for deploying tissue anchor system 180, describedhereinabove with reference to FIGS. 4A-B, for repairing a tricuspidvalve 504, in accordance with an application of the present invention.In the particular method shown in these figures, first and second tissueanchors 182A and 182B of tissue anchor system 180 comprise first tissueanchor 120 and stent 186, described hereinabove with reference to FIG.4B. The method may also be used to deploy other tissue anchors describedherein, mutatis mutandis. Tissue anchor system 180 further comprisesdeployment tool 30, for deploying first tissue anchor 182A, and,typically, a second anchor delivery tool for deploying second tissueanchor 182B.

As shown in FIG. 13A, first anchor deployment tool 30 is advanced,during a transcatheter procedure (typically endovascularly, such aspercutaneously), via a catheter 506, with the aid of a guidewire,through vasculature of the subject, and into a cardiac chamber, such asa right atrium 500 toward a first implantation site 530 at tricuspidvalve 504 through an inferior vena cava 508 from a suitable point ofentry. Alternatively, the delivery tool may be advanced through asuperior vena cava 510. First tissue anchor 182A is constrained withinfirst anchor deployment tool 30, such as described hereinabove withreference to FIG. 1A. The procedure is typically performed with the aidof imaging, such as fluoroscopy, transesophageal, transthoraticechocardiography, ICE, and/or echocardiography.

Also as shown in FIG. 13A, first anchor deployment tool 30 is advancedthrough the wall of the heart by advancing sharp distal piercing tip 32of the tool through first implantation site 530. Successful passagethrough the wall is typically confirmed using imaging. Firstimplantation site 530 is shown as within 1 cm of the site on the annulusthat circumferentially corresponds to a circumferential middle 521 of ananterior leaflet 586; alternative first implantation sites 530 are setforth hereinbelow in Table 1. For some applications, first implantationsite 530 is within 10 mm, such as within 5 mm, of RCA 590.

As shown in FIG. 13B, first tissue anchor 182A is partially releasedfrom first anchor deployment tool 30 such that tissue-coupling element128 is unconstrained by first anchor deployment tool 30. The surgeonascertains, typically using imaging, whether tissue-coupling element 128overlies a coronary blood vessel, such as RCA 590. In the procedureshown in FIG. 13B, tissue-coupling element 128 does overlie a coronaryblood vessel (RCA 590).

For some applications, such as shown in FIGS. 13A-D, first anchordeployment tool 30, and first tissue anchor 182A, exit the heart at anexternal exit site 550 on right atrium 500. Typically, in theseapplications, first tissue anchor 182A passes through an atrial portionof the annulus, or an edge of the annulus and the origin of thetrabeculae carneae. For other applications, such as describedhereinbelow with reference to FIG. 16, first anchor deployment tool 30,and first tissue anchor 182A, exit the heart at external exit site 550on a right ventricle 552. Typically, in these applications, first tissueanchor 182A passes under RCA 590 in the annulus and exits on theventricular wall.

If tissue-coupling element 128 overlies a coronary blood vessel (e.g.,RCA 590), the surgeon rotates first tissue anchor 182A (clockwise and/orcounterclockwise, about central longitudinal axis 134) untiltissue-coupling element 128 no longer overlies the coronary bloodvessel, as shown in FIG. 13C. The rotation is typically performed byrotating shaft 122. The surgeon brings tissue-coupling element 128 intocontact with an external surface 534 of the heart, by proximallyretracting first tissue anchor 182A.

After first tissue anchor 182A has been implanted at first implantationsite 530, deployment tool 30 is removed from the subject's body,typically leaving catheter 506 in situ.

As shown in FIG. 13D, second tissue anchor 182B is implanted in thesubject at a second implantation site 540. For example, as shown, secondtissue anchor 182B may comprise stent 186, and second implantation site540 may be inferior vena cava 508; an alternative second implantationsite 540 is set forth hereinbelow in Table 1. Tension is applied to theone or more tethers 132 that couple the first tissue anchor 182A (e.g.,the head thereof) to second tissue anchor 182B. Application of suchtension facilitates repair of an atrioventricular valve of the subject,such as tricuspid valve 504.

For some applications, second tissue anchor 182B is implanted in thesubject, and first tissue anchor 182A is coupled to second tissue anchor182B by the one or more tethers 132 using the techniques described forconnecting first and second tissue-engaging elements 60 a and 60 b in USPatent Application Publication 2014/0114390 with reference to FIGS.34A-E thereof; the '390 publication is incorporated herein by reference.For some applications, one of the one or more tethers 132 is fixed toone of (a) first tissue anchor 182A and (b) second tissue anchor 182B.For some applications, first and second tissue anchors 182A and 182B areimplanted using techniques described in US Patent ApplicationPublication 2012/0035712 with reference to FIGS. 7A-D and/or FIGS. 11A-Bthereof; the '715 publication is incorporated herein by reference.

Reference is now made to FIGS. 14A-D, which are schematic illustrationsof a method for deploying tissue anchor system 248, describedhereinabove with reference to FIGS. 6A-B, for repairing tricuspid valve504, in accordance with an application of the present invention. In theparticular method shown in these figures, first and second tissueanchors 182A and 182B of tissue anchor system 248 comprise first tissueanchor 300, described hereinabove with reference to FIGS. 9A-G, andstent 186, described hereinabove with reference to FIG. 6B. The methodmay also be used to deploy other tissue anchors described herein,mutatis mutandis. Tissue anchor system 248 further comprises deploymenttool 30, for deploying first tissue anchor 182A, and, typically, asecond anchor delivery tool for deploying second tissue anchor 182B.

As shown in FIG. 14A, first anchor deployment tool 30 is advanced,during a transcatheter procedure (typically endovascularly, such aspercutaneously), such as described hereinabove with reference to FIG.13A. Also as shown in FIG. 14A, first anchor deployment tool 30 isadvanced through the wall of the heart by advancing sharp distalpiercing tip 32 of the tool through first implantation site 530.Successful passage through the wall is typically confirmed usingimaging. First implantation site 530 is shown as within 1 cm of the siteon the annulus that circumferentially corresponds to circumferentialmiddle 521 of anterior leaflet 586; alternative first implantation sites530 are set forth hereinbelow in Table 1. For some applications, firstimplantation site 530 is within 10 mm, such as within 5 mm, of RCA 590.

As shown in FIG. 14B, first tissue anchor 182A is partially releasedfrom first anchor deployment tool 30 such that tissue-coupling element128 is unconstrained by first anchor deployment tool 30. The surgeonascertains, typically using imaging, whether tissue-coupling element 128overlies a coronary blood vessel, such as RCA 590. In the procedureshown in FIG. 14B, tissue-coupling element 128 does overlie a coronaryblood vessel (RCA 590).

For some applications, such as shown in FIGS. 14A-D, first anchordeployment tool 30, and first tissue anchor 182A, exit the heart atexternal exit site 550 on right atrium 500. Typically, in theseapplications, first tissue anchor 182A passes through an atrial portionof the annulus, or an edge of the annulus and the origin of thetrabeculae carneae. For other applications, such as describedhereinbelow with reference to FIG. 16, first anchor deployment tool 30,and first tissue anchor 182A, exit the heart at external exit site 550on right ventricle 552. Typically, in these applications, first tissueanchor 182A passes under RCA 590 in the annulus and exits on theventricular wall.

If tissue-coupling element 128 overlies a coronary blood vessel (e.g.,RCA 590), the surgeon rotates first tissue anchor 182A (clockwise and/orcounterclockwise, about central longitudinal axis 134) untiltissue-coupling element 128 no longer overlies the coronary bloodvessel, as shown in FIG. 14C. The rotation is typically performed byrotating shaft 122. The surgeon brings tissue-coupling element 128 intocontact with an external surface 534 of the heart, by proximallyretracting first tissue anchor 182A.

Providing the tissue anchor (e.g., tissue anchor 300) with an ellipticalshape (or paper clip shape) reduces the risk of contact with a sensitiveanatomic structure, such as a blood vessel, e.g., the RCA.

After first tissue anchor 182A has been implanted at first implantationsite 530, driver 201 is decoupled from the anchor head and deploymenttool 30 is removed from the subject's body, typically leaving catheter506 in situ.

As shown in FIG. 14D, second tissue anchor 182B is implanted in thesubject at second implantation site 540. For example, as shown, secondtissue anchor 182B may comprise stent 186, and second implantation site540 may be inferior vena cava 508; an alternative second implantationsite 540 is set forth hereinbelow in Table 1. Tension is applied to theone or more tethers 132 that couple the first tissue anchor 182A (e.g.,flexible elongate tension member 202 thereof) to second tissue anchor182B. Typically, the tension is applied without applying tension toshaft 122. Application of such tension facilitates repair of anatrioventricular valve of the subject, such as tricuspid valve 504.

For some applications, second tissue anchor 182B is implanted in thesubject, and first tissue anchor 182A is coupled to second tissue anchor182B by the one or more tethers 132 using the techniques described forconnecting first and second tissue-engaging elements 60 a and 60 b in USPatent Application Publication 2014/0114390 with reference to FIGS.34A-E thereof; the '390 publication is incorporated herein by reference.For some applications, one of the one or more tethers 132 is fixed toone of (a) first tissue anchor 182A and (b) second tissue anchor 182B.For some applications, first and second tissue anchors 182A and 182B areimplanted using techniques described in US Patent ApplicationPublication 2012/0035712 with reference to FIGS. 7A-D and/or FIGS. 11A-Bthereof; the '715 publication is incorporated herein by reference.

The following Table 1 sets forth exemplary combinations of (a)anatomical markers for first implantation site 530, (b) secondimplantation site 540, and (c) external exit sites 550. These sites arelisted by way of example and not limitation; the surgeon typicallyselects the exact sites based on the subject's individual needs andanatomy. Any appropriate location on the heart wall may be used. Firstimplantation site 530 is located within 1 cm of the site on the annulusthat circumferentially corresponds to the anatomical marker (i.e., is atthe same angular location or “o'clock” as the respective anatomicalmarker). The direction of the 1 cm from the site on the annulus may beeither circumferentially (i.e., clockwise or counterclockwise) aroundthe annulus, up the wall of the right atrium above the annulus, or acombination of circumferentially around the annulus and up the wall ofthe atrium.

Typically, the surgeon uses the anatomical markers to find the exactlocation first implantation site 530, which is within 1 cm of theanatomical markers, as described above. For example, the commissures areeasily detectable using imaging, and thus represent good anatomicalmarkers. However, the commissures are not appropriate for implantation(because they are too delicate), so, in this example, the anchors areimplanted near the annulus, such as up the wall of the atrium, within 1cm from the commissure.

TABLE 1 First implantation site 530 Second implantation External exitanatomical marker site 540 site 550 Circumferential middle Inferior venacava 508 Right atrium 500 521 of anterior leaflet (site 550A in FIG. 16)586 An anteroposterior Inferior vena cava 508 Right atrium 500commissure 512 (site 550B in FIG. 16) Circumferential middle Inferiorvena cava 508 Right ventricle 552 521 of anterior leaflet (site 550C inFIG. 16) 586 Anteroposterior Inferior vena cava 508 Right ventricle 552commissure 512 (site 550D in FIG. 16) A circumferential Superior venacava 510 Right ventricle 552 middle of a posterior (site 550C in FIG.16) leaflet Anteroposterior Superior vena cava 510 Right ventricle 552commissure 512 (site 550D in FIG. 16) Circumferential middle A coronarysinus Right atrium 500 521 of anterior leaflet (site 550A in FIG. 16)586

Reference is now made to FIGS. 15A-C, which are schematic illustrationsof another method for deploying tissue anchor system 180 or tissueanchor system 248 for repairing tricuspid valve 504, in accordance withan application of the present invention. In the particular method shownin these figures, first tissue anchor 182A of tissue anchor system 180comprises first tissue anchor 120, and second tissue anchor 182B oftissue anchor system 180 comprises helical tissue-coupling element 184,described hereinabove with reference to FIG. 4A. For some applications,second tissue anchor 182B comprises tissue anchor 724, describedhereinbelow with reference to FIGS. 17A-18B. The method may also be usedto deploy other tissue anchors described herein, including tissue anchor200 or 300 of tissue anchor system 248 as the first tissue anchor,mutatis mutandis. Tissue anchor system 180 or tissue anchor system 248further comprises deployment tool 30, for deploying first tissue anchor182A, and, typically, a second anchor delivery tool 570 for deployingsecond tissue anchor 182B. For some applications, second anchor deliverytool 570 comprises a torque-delivery tool 720, described hereinbelowwith reference to FIGS. 17A-18B. Tissue anchor system 180 or tissueanchor system 248 allows first and second tissue anchors 182A and 182Bto be delivered separately and connected afterwards in situ. Thissimplifies the procedure for the operator, and allows an approach fromtwo or more different blood vessels such as transfemoral, transjugular,transradial or transapical approaches, which may provide simpler accessto the anchoring point.

First tissue anchor 182A is implanted as described hereinabove withreference to FIGS. 13A-D or FIGS. 13A-D, as appropriate. As mentionedabove, first implantation site 530 is shown as circumferential middle521 of anterior leaflet 586; alternative first implantation sites 530are set forth hereinbelow in Table 2. As mentioned with reference toFIG. 13C, after first tissue anchor 182A has been implanted at firstimplantation site 530, deployment tool 30 is removed from the subject'sbody, typically leaving catheter 506 in situ.

As shown in FIG. 15A, second tissue anchor 182B is implanted in thesubject at second implantation site 540. For example, second tissueanchor 182B may comprise helical tissue-coupling element 184, describedhereinabove with reference to FIG. 4A, and second implantation site 540may be within 1 cm of a site on the annulus that circumferentiallycorresponds to a septoposterior commissure 517; alternative secondimplantation sites 540 are set forth hereinbelow in Table 2. For someapplications, the one or more tethers 132 comprise a single tether 132.For some applications, tether 132 defines a plurality of securementprotrusions 560 spaced at intervals along tether 132, which protrusionsserve as the friction-enhancing features. For some applications, asshown, protrusions 560 comprise respective cylinders on tether 132.

For some applications, outside the subject's body, the surgeon threads afree end of tether 132 through a lateral opening 582 of an outertether-securing element 580 of second tissue anchor 182B, and thenthrough a lumen of a delivery tube 614. Tether 132 thus connects firstand second tissue anchors 182A and 182B.

For some applications, as shown in FIG. 15A, second tissue anchor 182Bis implanted at second implantation site 540 using a torque-deliverycable 728 of torque-delivery tool 720, described hereinbelow withreference to FIGS. 17A-18B. Second tissue anchor 182B andtorque-delivery cable 728 are introduced over tether 132 and throughdelivery tube 614, which itself is advanced through catheter 506. Atether-locking mechanism of second tissue anchor 182B is introduced inan unlocked state in which sliding of tether 132 through a lateralopening 782 of second tissue anchor 182B is not inhibited. Second tissueanchor 182B is implanted at second implantation site 540 by rotatingtorque-delivery cable 728 (including a torque-delivery head 730).

The size of the tricuspid valve orifice is reduced by tensioning tether132, so as to reduce regurgitation. Such tensioning may be performed byproximally pulling on the free end of tether 132, such that a portion oftether 132 is pulled through lateral opening 582 of second tissue anchor182B. This tension can be applied remotely, i.e., via catheter 506.Application of such tension facilitates repair of an atrioventricularvalve of the subject, such as tricuspid valve 504.

As shown in FIG. 15B, once the tension has been applied, torque-deliverycable 728 (including torque-delivery head 730) is decoupled from secondtissue anchor 182B, such as by removing a locking wire. As a result, aspring 770 expands and presses tether 132 against an outertether-securing element 780, both of which are described hereinbelowwith reference to FIGS. 17A-18B. This pressing transitions thetether-locking mechanism to a locked state, in which state the slidingof tether 132 through the second tissue anchor 182B is inhibited. Suchlocking maintains the distance and tension between second tissue anchor182B and first tissue anchor 182B.

As shown in FIG. 15C, after tether 132 has been tensioned, an excessportion of tether 132 remains free in the right atrium. It is generallyundesirable to leave this excess portion free to move around in theatrium. For some applications, the excess portion of tether 132 is cutand removed from the atrium, using a cutting tool, such as thoracoscopicscissors, as known in the art. Further alternatively, for someapplications, the excess portion is secured in a desired disposition inthe vasculature of the right atrium, such as in inferior vena cava 508,superior vena cava 510, or a coronary sinus.

The following Table 2 sets forth exemplary combinations of (a)anatomical markers for first implantation site 530, (b) anatomicalmarkers for second implantation site 540, and (c) external exit sites550. These sites are listed by way of example and not limitation; thesurgeon typically selects the exact sites based on the subject'sindividual needs and anatomy. Each of first and second implantationsites 530 and 540 is located within 1 cm of the site on the annulus thatcircumferentially corresponds to the respective anatomical marker (i.e.,is at the same angular location or “o'clock” as the respectiveanatomical marker). The direction of the 1 cm from the site on theannulus may be either circumferentially (i.e., clockwise orcounterclockwise) around the annulus, up the wall of the right atriumabove the annulus, or a combination of circumferentially around theannulus and up the wall of the atrium. For example, as shown in FIG.15C, septoposterior commissure 517 is near, but not on, the annulus, andsecond tissue anchor 182B is shown implanted at second implantation site540, which is at the site on the annulus that circumferentiallycorresponds to this commissure. Second implantation site 540 could alsobe up to 1 cm clockwise or counterclockwise around the annulus from thissite on the annulus, up to 1 cm up the wall of the atrium, or acombination of these two directions.

Typically, the surgeon uses the anatomical markers to find the exactlocations of first and second implantation sites 530 and 540, which arewithin 1 cm of the anatomical markers, as described above. For example,the commissures are easily detectable using imaging, and thus representgood anatomical markers. However, the commissures are not appropriatefor implantation (because they are too delicate), so, in this example,second tissue anchor 182B is implanted on the annulus or up the wall ofthe atrium, within 1 cm from the commissure.

TABLE 2 First implantation Second implantation site 530 site 540External exit anatomical marker anatomical marker site 550Circumferential middle Septoposterior commissure Right atrium 500 521 ofanterior leaflet 517 586 Anteroposterior Septoposterior commissure Rightatrium 500 commissure 512 517 Circumferential middle Septoposteriorcommissure Right ventricle 552 521 of anterior leaflet 517 586Anteroposterior Septoposterior commissure Right ventricle 552 commissure512 517

Reference is now made to FIG. 16, which is a schematic illustration ofseveral external exit sites 550, in accordance with respectiveapplications of the present invention. External exit sites 550 aretypically within 10 mm, such as 5 mm, of RCA 590 or branches from theRCA such as the posterior descending artery (PDA) or veins of the rightventricle. External exit sites 550A and 550C are on right atrium 500,and external exit sites 550B and 550D are on right ventricle 552.

For some applications, both first and second tissue anchors 182A and182B comprise respective tissue anchors 20 (tissue anchors 120,described hereinabove with reference to FIGS. 1A-3B; tissue anchor 200,described hereinabove with reference to FIGS. 5A-7B; tissue anchor 258,described hereinabove with reference to FIGS. 8A-B; tissue anchor 220,described hereinabove with reference to FIGS. 10A-B; tissue anchor 300,described hereinabove with reference to FIGS. 9A-G; tissue anchor 290,described hereinabove with reference to FIG. 9H; tissue anchor 320,described hereinabove with reference to FIGS. 11A-C; tissue anchor 420,described hereinabove with reference to FIGS. 12A-C; or a combination oftwo different ones of these tissue anchors). For some applications,first tissue anchor 182A is implanted at an implantation site locatedwith 1 cm of the site on the annulus that circumferentially correspondsto an anatomical marker between circumferential middle 521 of anteriorleaflet 586 and anteroposterior commissure 512, inclusive. Alternativelyor additionally, for some applications, second tissue anchor 182B isimplanted at an implantation site located with 1 cm of the site on theannulus that circumferentially corresponds to an anatomical markerbetween a circumferential middle of a posterior leaflet andseptoposterior commissure 517, inclusive.

Further alternatively or additionally, for some applications, secondtissue anchor 182B is implanted at an implantation site located abovethe triangle of Koch, through the septal muscle into the left atriumabove the level of the mitral valve. The off-centeredness of tissueanchors 120, 200, 220, 300, 320, and 420 allows the tissue-couplingelement to be rotated during implantation so as to avoid contact withthe mitral valve if the anchor enters the left atrium lower thanexpected. For some of these applications, first tissue anchor 182Acomprises a stent, such as described hereinabove, which may be connectedto second tissue anchor 182B by one or more tethers, at least one ofwhich passes through a pulley, such as described in PCT Publication WO2015/063580, which is incorporated herein by reference. Alternatively,the anchors are implanted and coupled to one another under tension usingthe techniques described hereinbelow with reference to FIG. 15B, mutatismutandis.

For some applications, the head of second tissue anchor 182B comprisesproximal anchor head 752, described hereinbelow with reference to FIGS.17A-18B (and second tissue anchor 182B comprises one of tissue-couplingelements described hereinabove, as mentioned above).

FIGS. 17A-F are schematic illustrations of a tissue-anchor system 710 inan unlocked state, in accordance with an application of the presentinvention. FIGS. 18A-B are schematic illustrations of tissue-anchorsystem 710 in a locked state, in accordance with an application of thepresent invention. Tissue-anchor system 710 comprises torque-deliverytool 720, tether 132, and tissue anchor 724. Torque-delivery tool 720 isconfigured to implant tissue anchor 724 in cardiac tissue, and tothereafter lock tether 132 to tissue anchor 724, such that sliding oftether 132 with respect to tissue anchor 724 is inhibited. Typically,tether 132 is tensioned after tissue anchor 724 has been implanted inthe cardiac tissue, and after the tether has been tensioned, tether 132is locked to tissue anchor 724.

Torque-delivery tool 720 comprises (a) torque-delivery cable 728, whichcomprises distal torque-delivery head 730, (b) a distal coupling element732 that is fixed to a distal end 734 of torque-delivery head 730, and(c) a distal spring depressor 736.

Tissue anchor 724 comprises (a) a tissue-coupling element 750, and (b) aproximal anchor head 752, which is attached to a proximal portion 754 oftissue-coupling element 750. For some applications, tissue-couplingelement 750 comprises a helical tissue-coupling element, which puncturesand screws into cardiac tissue. For some applications, tissue-couplingelement 750 implements features of one or more of the tissue-couplingelements described in PCT Publication WO 2014/108903, which isincorporated herein by reference.

Anchor head 752 comprises an axially-stationary shaft 756 and atether-locking mechanism 768. Axially-stationary shaft 756 (which canbest be seen in FIGS. 17D-F) has (a) a distal portion 758 that isaxially fixed with respect to proximal portion 754 of tissue-couplingelement 750, and (b) a proximal end 760 that comprises a proximalcoupling element 762. Distal and proximal coupling elements 732 and 762are shaped so as to define corresponding interlocking surfaces, whichfacilitate coupling of torque-delivery head 730 to axially-stationaryshaft 756.

Tether-locking mechanism 768 comprises:

-   -   spring 770 (which can best be seen in FIG. 17D) (for clarity of        illustration of other elements, spring 770 is not shown in FIGS.        17E-F; the spring is actually present); and    -   outer tether-securing element 780, which (a) is shaped so as to        define lateral opening 782 through which tether 132 is disposed,        and (b) at least partially radially surrounds axially-stationary        shaft 756 and spring 770 (and hammer cap 800, if provided, as        described below). For some applications, as shown in the        figures, outer tether-securing element 780 is shaped as a        partial cylinder.

For some applications, at least a portion of spring 770 radiallysurrounds axially-stationary shaft 756, such as shown in FIG. 17D. Forsome applications, at least a portion of spring 770 is helical, such asshown in FIGS. 17D and 18A-B (e.g., the entire spring is helical, suchas shown in FIGS. 17D and 18A-B), while for other applications, spring770 is not helical.

Tissue-anchor system 710 is configured to assume:

-   -   an unlocked state, as shown in FIGS. 17A-F, in which (a) distal        and proximal coupling elements 732 and 762 are interlockedly        coupled with one other, and (b) distal spring depressor 736        restrains spring 770 in an axially-compressed state, in which        state spring 770 does not inhibit sliding of tether 132 through        lateral opening 782, and    -   a locked state, as shown in FIGS. 18A-B, in which (a) distal and        proximal coupling elements 732 and 762 are not coupled with one        another, (b) distal spring depressor 736 does not restrain        spring 770 in the axially-compressed state, and (c) spring 770        is in an axially-expanded state, in which state spring 770        inhibits the sliding of tether 132 through lateral opening 782        by pressing tether 132 against outer tether-securing element        780, such as against a perimeter 784 of lateral opening 782,        and/or an inner surface of outer tether-securing element 780.

When tissue-anchor system 710 is in the unlocked state, tether-lockingmechanism 768 is also in an unlocked state, in which state spring 770does not inhibit sliding of tether 132 through lateral opening 782. Whentissue-anchor system 710 is in the locked state, tether-lockingmechanism 768 is also in a locked state, in which state spring 770inhibits the sliding of tether 132 through lateral opening 782 bypressing tether 132 against outer tether-securing element 780, such asagainst perimeter 784 of lateral opening 782, and/or an inner surface ofouter tether-securing element 780.

Tissue-anchor system 710 is advanced into the heart in the unlockedstate. Tissue anchor 724 is implanted in cardiac tissue, usingtorque-delivery cable 728 while tissue-anchor system 710 is in theunlocked state. After tissue anchor 724 is implanted, tension is appliedto tether 132. Thereafter, torque-delivery cable 728 (includingtorque-delivery head 730) is decoupled from axially-stationary shaft 756of tissue anchor 724, thereby allowing spring 770 to expand and presstether 132 against outer tether-securing element 780. This pressinglocks tether 132 with respect to tissue anchor 724, and maintains thedistance and tension between tissue anchor 724 and one or more otherimplanted tissue anchors, such as described hereinabove with referenceto FIGS. 15A-C. Alternatively, tissue-anchor system 710 is used toimplant tissue anchor 24 in non-cardiac tissue of a subject, in whichcase tissue-anchor system 10 is advanced into another location in thesubject's body.

Torque-delivery cable 728 (including torque-delivery head 730) thusserves two functions:

-   -   implanting tissue anchor 724 in cardiac tissue, by applying a        rotational force to tissue anchor 724; and    -   maintaining tissue-anchor system 710 in the unlocked state, in        which state tether 132 can slide with respect to tissue anchor        724, allowing tension to be applied to the tether (and adjusted        as necessary).

Similarly, decoupling of torque-delivery cable 728 (includingtorque-delivery head 730) from axially-stationary shaft 756 of anchorhead 752 of tissue anchor 724 simultaneously (1) releases tissue anchor724 and (2) transitions tissue-anchor system to the locked state.

For some applications, as can be seen in FIGS. 17A-C and FIGS. 18A-B,anchor head 752 further comprises a hammer cap 800, which is fixed tospring 770, and covers at least a portion 802 of spring 770, including aproximal end 804 of spring 770. (For clarity of illustration of otherelements, hammer cap 800 is not shown in FIGS. 17D-F; the hammer cap isoptionally present.) When tissue-anchor system 710 is in the lockedstate, spring 770 presses tether 132 against outer tether-securingelement 780 by pressing hammer cap 800 against outer tether-securingelement 780, such as perimeter 784 of lateral opening 782, and/or aninner surface of outer tether-securing element 780. Hammer cap 800 mayprevent entanglement of tether 132 with spring 770. In addition,providing hammer cap 800 may obviate the need to weld a distal end ofspring 770 to anchor head 752, because the hammer cap surrounds at leasta portion of the spring and thereby couples the spring to the anchorhead. For some applications, tether 132 prevents hammer cap 800 fromproximally exiting outer tether-securing element 780. Alternatively oradditionally, for some applications, one or more small pins 808 (shownin FIG. 18A) are provided that extend radially inward from an innersurface of outer tether-securing element 780; the pins prevent thehammer cap from proximally exiting the outer tether-securing element.

For some applications, tissue-anchor system 710 further comprises alocking wire 810. Torque-delivery cable 728 (including torque-deliveryhead 730), distal coupling element 732, proximal coupling element 762,and axially-stationary shaft 756 are shaped so as define respectivechannels 772, 774, 776, and 778 therethrough, which are radially alignedwith each other and coaxial with tissue anchor 724. When tissue-anchorsystem 710 is in the unlocked state, a portion of locking wire 810 isdisposed in the channels, thereby preventing decoupling of distal andproximal coupling elements 732 and 762 from one another. Proximalwithdrawal and removal of the portion of locking wire 810 from thechannels allows the decoupling of distal and proximal coupling elements732 and 762 from one another.

For some applications, locking wire 810 is shaped so as to define asharp distal tip 822. For these applications, tissue-coupling element750 typically is helical, and locking wire 810 is initially removablypositioned within a channel defined by the helix. As tissue-couplingelement 750 is screwed into tissue, locking wire 810 penetrates andadvances into the tissue along with the anchor to a certain depth in thetissue. For some applications, when the shaft penetrates to the certaindepth, the locking wire is withdrawn slightly. Typically, aftertissue-coupling element 750 has been fully implanted, locking wire 810is withdrawn entirely from the tissue, and removed from the subject'sbody. Optionally, sharp distal tip 822 of locking wire 810 is insertedinto the tissue slightly, even before insertion of tissue-couplingelement 750, in order to inhibit sliding of the tissue-coupling elementon the surface of the tissue before commencement of insertion of thetissue-coupling element into the tissue.

For some applications, outer tether-securing element 780 is rotatablewith respect to tissue-coupling element 750 and axially-stationary shaft756, in order to provide rotational freedom of movement to tether 132after implantation of tissue anchor 724, particularly during tensioningof tether 132. This rotational freedom of movement avoids twisting ofthe tether around the anchor head, and facilitates ideal orientation ofthe tether with another tissue anchor.

For some applications, outer tether-securing element 780 has an outerdiameter of at least 1 mm, no more than 6 mm, and/or between 1 and 6 mm.For some applications, tissue anchor 724 has an outer diameter of atleast 2 mm, no more than 8 mm, and/or between 2 and 8 mm.

Although the techniques described herein have been described as beingused to remodel the tricuspid valve, these techniques may also be usedto remodel the mitral valve, mutatis mutandis. In addition, the tissueanchors described herein may be implanted on the surface of any wall ofthe heart or other organ where tension is to be applied, androtationally repositioned to avoid obstructions of anatomic structuressuch as blood vessels or conduction systems, or pre-existing implants.

As used in the present application, including in the claims, when arange of values is specified using the word “between,” the rangeincludes the endpoint values.

The scope of the present invention includes embodiments described in thefollowing applications, which are assigned to the assignee of thepresent application and are incorporated herein by reference. In anembodiment, techniques and apparatus described in one or more of thefollowing applications are combined with techniques and apparatusdescribed herein:

-   -   U.S. Pat. No. 8,475,525 to Maisano et al.;    -   U.S. Pat. No. 8,961,596 to Maisano et al.;    -   U.S. Pat. No. 8,961,594 to Maisano et al.;    -   International Application PCT/IL2011/000064, filed Jan. 20,        2011, which published as PCT Publication WO 2011/089601, and        U.S. application Ser. No. 13/574,088 in the national stage        thereof, which published as US Patent Application Publication        2013/0046380;    -   U.S. application Ser. No. 13/553,081, filed Jul. 19, 2012, which        published as US Patent Application Publication 2013/0018459;    -   International Application PCT/IL2012/000282, filed Jul. 19,        2012, which published as PCT Publication WO 2013/011502;    -   U.S Provisional Application 61/750,427, filed Jan. 9, 2013;    -   U.S. Provisional Application 61/783,224, filed Mar. 14, 2013;    -   International Application PCT/IL2013/050470, filed May 30, 2013,        which published as PCT Publication WO 2013/179295;    -   U.S. Provisional Application 61/897,491, filed Oct. 30, 2013;    -   U.S. Provisional Application 61/897,509, filed Oct. 30, 2013;    -   U.S. application Ser. No. 14/143,355, filed Dec. 30, 2013, which        published as US Patent Application Publication 2014/0114390;    -   International Application PCT/IL2014/050027, filed Jan. 9, 2014,        which published as PCT Publication WO 2014/108903;    -   International Application PCT/IL2014/050233, filed Mar. 9, 2014,        which published as PCT Publication WO 2014/141239;    -   U.S. Provisional Application 62/014,397, filed Jun. 19, 2014;    -   International Application PCT/IBB2014/002351, filed Oct. 28,        2014, which published as PCT Publication WO 2015/063580;    -   U.S. application Ser. No. 14/525,668, filed Oct. 28, 2014, which        published as US Patent Application Publication 2015/0119936;    -   U.S. Provisional Application 62/086,269, filed Dec. 2, 2014;    -   U.S. Provisional Application 62/131,636, filed Mar. 11, 2015;    -   U.S. Provisional Application 62/167,660, filed May 28, 2015; and    -   International Application PCT/IB2015/001196, filed Jun. 14,        2015, which published as PCT Publication WO 2015/193728.

Patents and patent application publications incorporated by reference inthe present patent application are to be considered an integral part ofthe application except that to the extent any terms are defined in theseincorporated patents and patent application publications in a mannerthat conflicts with the definitions made explicitly or implicitly in thepresent specification, only the definitions in the present specificationshould be considered. In particular, the definition of “spiral” providedin U.S. Provisional Application 62/086,269, filed Dec. 2, 2014, and U.S.Provisional Application 62/167,660, filed May 28, 2015 should not beconsidered.

It will be appreciated by persons skilled in the art that the presentinvention is not limited to what has been particularly shown anddescribed hereinabove. Rather, the scope of the present inventionincludes both combinations and subcombinations of the various featuresdescribed hereinabove, as well as variations and modifications thereofthat are not in the prior art, which would occur to persons skilled inthe art upon reading the foregoing description.

1. Apparatus for delivery through tissue in a constrained state within adeployment tool, the apparatus comprising a tissue anchor, whichcomprises: a shaft, which comprises a seal; a head connected to aproximal portion of the shaft; and a tissue-coupling element, whichextends from a distal end of the shaft, wherein, when the tissue anchoris unconstrained by the deployment tool: the shaft has a centrallongitudinal axis, the head is coaxial with the central longitudinalaxis, and the tissue-coupling element is generally orthogonal to thecentral longitudinal axis of the shaft and is shaped such that if thetissue-coupling element were to be projected onto a plane that isperpendicular to the central longitudinal axis, (a) at least 80% of anarea of a projection of the tissue-coupling element on the plane wouldfall within a first angle of 180 degrees in the plane having a vertex atthe central longitudinal axis, and (b) the area would partially overlap,at least 3 mm from the vertex, both rays of a second angle of between 45and 180 degrees in the plane having the vertex at the centrallongitudinal axis.
 2. The apparatus according to claim 1, wherein atleast 95% of the area of the projection of the tissue-coupling elementon the plane would fall within the first angle.
 3. The apparatusaccording to claim 1, wherein at least 80% of the area of the projectionof the tissue-coupling element on the plane would fall within a thirdangle of 150 degrees in the plane having the vertex at the centrallongitudinal axis.
 4. The apparatus according to claim 1, wherein anouter portion of the area of the projection of the tissue-couplingelement on the plane would fall within all angular positions of a fourthangle of 90 degrees in the plane having the vertex at the centrallongitudinal axis, which outer portion consists of all points of thearea at least 3 mm from the vertex.
 5. The apparatus according to claim1, wherein the tissue-coupling element is non-helical when the tissueanchor is unconstrained by the deployment tool.
 6. The apparatusaccording to claim 1, wherein the central longitudinal axis is straightwhen the tissue anchor is unconstrained by the deployment tool.
 7. Theapparatus according to claim 1, wherein the shaft and thetissue-coupling element are integral to one another.
 8. The apparatusaccording to claim 7, wherein the shaft and the tissue-coupling elementcomprise a wire.
 9. The apparatus according to claim 1, wherein thetissue-coupling element comprises at least three tines that extendradially outward from the central longitudinal axis in respectivedirections that are fixed with respect to one another when the tissueanchor is unconstrained by the deployment tool.
 10. The apparatusaccording to claim 9, wherein tines comprise at least four tines. 11.The apparatus according to claim 1, wherein the tissue-coupling elementcomprises a wire.
 12. The apparatus according to claim 11, wherein thewire is shaped as an open shape.
 13. The apparatus according to claim11, wherein the wire is shaped as an open loop having more than oneturn, when the tissue anchor is unconstrained by the deployment tool.14. The apparatus according to claim 13, wherein the open loop is shapedas a spiral when the tissue anchor is unconstrained by the deploymenttool.
 15. The apparatus according to claim 13, wherein the tissue anchorfurther comprises a flexible elongate tension member, which includes (a)a distal portion that is fixed to a site on the open loop, (b) aproximal portion, which has a longitudinal segment that runs alongsideat least a portion of the shaft, and (c) a crossing portion, which (i)is disposed between the distal and the proximal portions along theflexible elongate tension member, and (ii) crosses at least a portion ofthe open loop when the tissue anchor is unconstrained by the deploymenttool.
 16. The apparatus according to claim 15, wherein a radius of theflexible elongate tension member is less than a radius of the wire. 17.The apparatus according to claim 15, wherein the apparatus furthercomprises one or more tethers, which are fixed to the flexible elongatetension member.
 18. The apparatus according to claim 15, wherein thetissue anchor is a first tissue anchor, and wherein the apparatusfurther comprises: a second tissue anchor, which is separate anddistinct from the first tissue anchor; and one or more tethers, whichare configured to couple (a) the flexible elongate tension member to (b)the second tissue anchor.
 19. The apparatus according to claim 18,wherein the second tissue anchor comprises a stent.
 20. The apparatusaccording to claim 15, wherein the tissue anchor is configured to allowrelative axial motion between the at least a portion of the shaft andthe longitudinal segment of the proximal portion of the flexibleelongate tension member when the tissue anchor is unconstrained by thedeployment tool.
 21. The apparatus according to claim 20, wherein thelongitudinal segment of the proximal portion of the flexible elongatetension member is coupled in sliding communication with the at least aportion of the shaft when the tissue anchor is unconstrained by thedeployment tool.
 22. The apparatus according to claim 21, wherein thetissue anchor comprises one or more annular elements, which are disposedaround the at least a portion of the shaft, and couple the flexibleelongate tension member in the sliding communication with the at least aportion of the shaft when the tissue anchor is unconstrained by thedeployment tool.
 23. The apparatus according to claim 11, wherein, whenthe tissue anchor is unconstrained by the deployment tool: the wire ofthe tissue-coupling element is shaped as an open loop having more thanone turn around a center point, and the wire extends from the distal endof the shaft at a radially-outer end of the open loop.
 24. The apparatusaccording to claim 23, wherein the open loop is shaped as a spiral whenthe tissue anchor is unconstrained by the deployment tool.
 25. Theapparatus according to claim 1, wherein the tissue anchor is a firsttissue anchor, and wherein the apparatus further comprises: a secondtissue anchor, which is separate and distinct from the first tissueanchor; and one or more tethers, which are configured to couple (a) thehead of the first tissue anchor to (b) the second tissue anchor.
 26. Theapparatus according to claim 25, wherein the second tissue anchorcomprises a stent.
 27. A method comprising: providing a tissue anchorthat comprises (a) a shaft, (b) a head connected to a proximal portionof the shaft, which comprises a seal. and (c) a tissue-coupling element,which extends from a distal end of the shaft; introducing, during atranscatheter procedure, the tissue anchor into a cardiac chamber of aheart of a subject, while the tissue-coupling element is constrained bya deployment tool; delivering the tissue-coupling element through a wallof the heart; and at least partially releasing the tissue anchor fromthe deployment tool such that (a) the tissue-coupling element isunconstrained by the deployment tool, (b) the head is coaxial with acentral longitudinal axis of the shaft, and (c) the tissue-couplingelement is generally orthogonal to the central longitudinal axis of theshaft and is shaped such that if the tissue-coupling element were to beprojected onto a plane that is perpendicular to the central longitudinalaxis, (i) at least 80% of an area of a projection of the tissue-couplingelement on the plane would fall within a first angle of 180 degrees inthe plane having a vertex at the central longitudinal axis, and (ii) thearea would partially overlap, at least 3 mm from the vertex, both raysof a second angle of between 45 and 180 degrees in the plane having thevertex at the central longitudinal axis.
 28. The method according toclaim 27, further comprising, after delivering the tissue-couplingelement through the wall of the heart: ascertaining whether thetissue-coupling element overlies a coronary blood vessel; and if thetissue-coupling element overlies the coronary blood vessel, rotating thetissue anchor until the tissue-coupling element no longer overlies thecoronary blood vessel.
 29. The method according to claim 27, furthercomprising, after delivering the tissue-coupling element through thewall of the heart, rotating the tissue anchor and bringing thetissue-coupling element into contact with an external surface of theheart.
 30. The method according to claim 29, wherein introducing thetissue anchor into the cardiac chamber comprises introducing the tissueanchor into an atrium of the heart, and wherein bringing thetissue-coupling element into contact with the external surface of theheart comprises bringing the tissue-coupling element into contact withan external surface of a ventricle of the heart.